William Wallace Bass spent thirty years building a business out of trails, cable trams, and a canyon most people thought was just scenery. Buried in that business was an asbestos claim in a side canyon named for the Colorado River itself — ore good enough that buyers in China and France paid to fireproof their theater curtains with it. A century later, the National Park Service still won't let you within 500 feet of what's left.

The short version

• William Wallace Bass filed a dozen-plus copper and asbestos claims along his own rim-to-rim trail network from the late 1880s through the early 1900s, stockpiling ore each winter.
• His main asbestos operation was in Hakatai Canyon, developed with a partner named John Waltenberg and served by a cable tram Bass built across the Colorado River.
• Bass timed his one big payday well: he shipped his high-grade ore during World War I, when mineral prices spiked, grossing roughly $10,000 in copper and selling six tons of asbestos at $1,500 a ton.
• He sold his valid claims outright in 1926 for $25,000 and retired to Wickenburg, Arizona, where he died in 1933.
• EPA lists the Bass Asbestos Mine site in its Superfund database, but it was never placed on the National Priorities List — it carries a “no further remedial action planned” designation, not an active federal cleanup.
• The current park rulebook closes the ground within 500 feet of the mine and its tailings to the public, citing both a significant cultural resource and public health risk from high asbestos fiber levels.

A trail-builder who also mined

Bass arrived in Williams, Arizona Territory in July 1883 and settled on the South Rim as one of the area’s first non-Native residents, years before the railroad or the national monument existed. He made his living building and running trails — rim to river, river to rim, eventually rim to rim — for tourists, pack strings, and hunting parties. Mining was folded into that same operation rather than separate from it: Bass filed on more than a dozen copper and asbestos claims along his own trail network and spent winters hauling out what he could.

By 1906 he’d built a cageway across the Colorado River strung on four steel cables, used to move tourists, animals, and hunting parties — and, per his own trail’s dual purpose, asbestos ore from his mines. It’s a useful snapshot of how marginal most Grand Canyon mining actually was in this era: the tourist trade and the mineral claims ran on the same infrastructure because neither one alone paid the bills.

The Hakatai Canyon operation

Bass’s main asbestos venture was in Hakatai Canyon — “Hakatai” is reportedly the Havasupai word for the Colorado River itself — where he partnered with John Waltenberg to develop the claim. By his 1917 retirement, Bass had built a second cable tram across the river specifically at Hakatai Canyon to move the ore out, in addition to whatever else his other river crossing near Shinumo Creek, about two and a half miles upstream, handled for his broader operations.

The timing mattered more than the engineering. Bass got his highest-grade ore out and shipped during World War I, when wartime demand pushed mineral prices up across the board. He grossed roughly $10,000 on copper and sold six tons of asbestos — at $1,500 a ton — to buyers as far away as China and France, plus customers in the eastern United States. Some of that French-bound asbestos went into fireproofing theater curtains, a detail preserved in a period photo caption of Bass and a helper “high-grading” ore at Hakatai Canyon around 1900.

For context: other prospectors of the era, men like Pete Berry and Ralph and Niles Cameron, filed hundreds of claims along the South Rim, and most were bogus — filed just to tie up land that might someday prove valuable, not because anyone intended to mine them seriously. Bass’s operation, by comparison, actually produced and actually sold ore. That put him ahead of most of his contemporaries, even if “ahead” still meant a few tons of asbestos and a modest copper haul over three decades of work.

Cashing out

Bass’s nest egg came less from digging than from selling. In 1926 he sold his valid mining claims outright to the Santa Fe Land Improvement Company for $25,000, on top of what he’d already made shipping ore during the war. That sale funded his family’s retirement to Wickenburg, Arizona, where Bass died in 1933 — sources give the date as either March 7 or simply “1933,” with no material dispute about the year. (His birth year is similarly inconsistent across sources — 1848 in one archival finding aid, 1849 in a biographical summary — a small discrepancy that doesn’t affect anything else in his record.)

What’s actually off-limits (and why)

The Bass Asbestos Mine shows up twice in the current Grand Canyon National Park Superintendent’s Compendium, the park’s official closure rulebook — once as item 2 and again, worded almost identically, as item 27. Both close the ground within 500 feet of the mine and its associated tailings, in Hakatai Canyon, to public entry without special written permission from the superintendent, under 36 CFR § 1.5(a)(2). The park’s own explanation cites two things at once: protecting a significant cultural resource, and protecting public health because of high levels of asbestos fiber, plus employee safety for anyone who does have to work near the site.

River travelers get a second, overlapping rule: the compendium separately bars visitation to the ground “immediately surrounding the mine, talus slope, and camp” at River Mile 111.4, specifically because of the asbestos hazard. And underneath both of those site-specific rules sits the park’s blanket policy on every mine within its boundaries — Bass’s included — which defines “mine” broadly (adits, shafts, pits, tunnels, prospects, tailings piles) and closes all of them to public presence, use, and access without a permit, citing sensitivity and danger.

What’s notably absent is anything resembling Orphan Mine’s decades-long federal cleanup saga. EPA’s Superfund database lists a site profile for the Bass Asbestos Mine (EPA ID AZD981680309), but it’s flagged NFRAP — “no further remedial action planned” — and was never placed on the National Priorities List. No public record found this session describes a phased federal remediation program here comparable to Orphan Mine’s. As far as the documented record goes, the 500-foot buffer and permission requirement is the operative protection, not an active cleanup. See the general rundown of what’s closed and why across the park for how that compares to other restricted sites.

Sources

1. Mining — Nature, Culture and History at the Grand Canyon (Grand Canyon Historical Society)
2. Mile by Mile: Hakatai Rapid — Western River Expeditions
3. William Wallace Bass biography — kaibab.org (Grand Canyon Prospector-Pioneer Society)
4. Bass Asbestos Mine Superfund Site Profile (EPA ID AZD981680309) — U.S. Environmental Protection Agency
5. Grand Canyon National Park Superintendent's Compendium, effective June 16, 2026 — National Park Service

Ninety-seven percent of Grand Canyon National Park sits on karst — rock that dissolves into caves. Some of those caves, over millions of years, collapsed and filled with ore, and people spent a century digging the ore back out. Caves and mines aren't two unrelated stories at Grand Canyon. Often they're the same hole, at two different points in its life.

The short version

• Almost all of Grand Canyon’s bedrock is karst, and the Redwall Limestone that hosts most of its caves is the same formation that hosts its uranium deposits — the two aren’t a coincidence of geography, they’re a shared origin.
• “Breccia pipes,” the vertical ore columns miners chased for a century, form when ancient caverns in that limestone collapse and later fill with metal-bearing groundwater. A uranium mine and a fossil cave can be the same feature at different points in its history.
• NPS estimates the park holds as many as 2,500 natural caves (several hundred formally documented, a more recent inventory puts it past 660) and, on the mining side, has counted 38 abandoned-mine sites with 75 individual features.
• Federal and park rules treat “cave” and “mine” as legally separate categories with separate closure justifications — but the same bats often live in both, which is where the rulebook and the biology reconnect.
• The park’s single most-studied cave system, found in 2008, has been mapped past 40 miles of passage and holds thousands of naturally mummified bats up to 50,000 years old — a scientific trove that has nothing to do with either mining or white-nose syndrome.

The shared geology nobody mentions on the rim trail

Start with the rock. Almost the entire park — 97% — sits on karst terrain, limestone and related rock riddled with the voids that water carves out over geologic time; another 3% is pseudokarst, similar-looking terrain formed by other processes. Only Everglades National Park has more karst area than Grand Canyon among all National Park Service units, and here it’s concentrated in one formation: the Redwall Limestone, the reddish-gray band about a third of the way down the canyon wall that hosts the majority of the park’s caves.

That same limestone is also where the canyon’s mining history comes from. “Breccia pipes” — the vertical, cylindrical ore bodies that produced nearly every uranium mine in and around the canyon — form when caverns inside the Redwall Limestone collapse under the weight of overlying rock, leaving a rubble-filled chimney that groundwater later saturates with dissolved metals, chiefly uranium and copper. It’s an unusual geologic mechanism, common in this part of northern Arizona and southern Utah and rare almost everywhere else; it’s also generous enough to have produced at least one mineral, grandviewite, found nowhere on Earth outside Grand Canyon. Put plainly: a breccia-pipe uranium mine isn’t built near an old cave. Structurally, it’s built inside one — a cave that collapsed, filled with ore, and got excavated a second time by people instead of water. The Orphan Mine, which pulled roughly 495,000 tons of ore and 4.26 million pounds of uranium oxide out of the South Rim between 1956 and 1969, is the best-documented example of this exact process.

Two different ways of counting holes

Ask NPS how many caves are in the park and you get an estimate with real uncertainty attached: as many as 2,500, with several hundred formally documented by the park’s Geodiversity Atlas, and a more recent, narrower figure from ongoing NPS-permitted survey work putting the documented count past 660. Ask about mines and you get something closer to an actual tally: 38 documented Abandoned Mineral Lands sites containing 75 individual features — adits, shafts, pits, tunnels, prospects, and tailings piles — with 12 of those 38 sites flagged as needing active mitigation. Those hazards run the range you’d expect from a century of hand-dug and machine-bored excavation: high radon, radioactive soils, asbestos, unstable debris, slope failure, and subsidence.

The two counts aren’t measuring the same thing the same way, and shouldn’t be added together. Caves are counted by exploration — someone has to physically find and survey a passage before it’s “documented,” and most of the park’s caves sit on cliff faces nobody has reason to visit. Mines are counted by federal environmental-liability inventory, a very different and more systematic process, because the government is legally obligated to track hazards on its own land. That gap in methodology is itself a small piece of the underground story: nature’s inventory is still being written by cavers with headlamps; industry’s inventory was closed out by federal accountants. For the full breakdown of what those 75 mine features are and where the money to close them has gone, see the mine inventory.

Same rock, different rulebook

Legally, the two categories don’t overlap at all. The Federal Cave Resource Protection Act of 1988 defines “cave” as a naturally occurring void and explicitly excludes “any vug, mine, tunnel, aqueduct, or other manmade excavation.” Grand Canyon’s current Superintendent’s Compendium, effective June 16, 2026, sharpens that further for management purposes — a natural opening only counts as a cave if it’s at least 50 feet long with an entrance no wider than it is deep — while defining “mine,” on the other side, as broadly as possible: any anthropogenic feature dug for mineral extraction, from a single 1890s prospect pit to a 1,500-foot uranium shaft. Both categories end up closed to the public by nearly parallel rules — mines need written superintendent permission for research or administrative work, caves need a valid entry permit — but for different stated reasons. Mine closures lead with safety. Cave closures lead with safety plus archaeology plus biology. For the full legal mechanics of that split, including why Redwall Cavern (a genuinely enormous natural feature on the river) technically fails the park’s own cave definition, see mines versus natural caves.

Where the rulebook’s clean split breaks down is biology. Nationally, 29 of the 45 bat species native to the U.S. rely on abandoned mines for some part of their life cycle — summer roosts, hibernation, nurseries — and Grand Canyon’s own mines are no exception; NPS says plainly that its abandoned copper, gold, and uranium workings “now make excellent habitat for many bat species.” That means a mine sealed for public safety and a cave sealed under Cave of the Domes’s bat-specific closure can be protecting the exact same colony, just under two different sections of the compendium. White-nose syndrome, the fungal disease that has killed millions of bats nationally since 2006 and was confirmed in Arizona for the first time in February 2025 — including trace detections in Coconino County, where the park itself sits — is the reason both categories now share the same decontamination protocol for anyone doing closure work near a roost.

The one cave nobody needed a mining company to find

Not every hole in this canyon has an industrial backstory, and the park’s best example proves it. In 2007-2008, caver Jason Ballensky located a cave system with no mining connection whatsoever — a purely natural discovery that has since been mapped past 40 miles of interconnected passage, ranking it among the longest known caves in the world, and it’s still not fully explored. Its location is kept undisclosed by NPS, and for good reason: the cave preserves hundreds, possibly thousands, of naturally mummified bats spanning at least 11 species, radiocarbon-dated from roughly 3,700 years old to beyond the ~50,000-year limit of the dating method itself, alongside preserved ringtails, foxes, raccoons, and rare gypsum-flower mineral formations. It’s a paleontological deposit, not a modern die-off — unrelated to white-nose syndrome — and it’s arguably the single best argument that this canyon’s underground is worth protecting on its own terms, independent of whatever was once mined out of it.

It’s also worth saying what this canyon’s underground definitely isn’t: there’s no lost Egyptian city, no hidden ancient civilization’s tunnel network, whatever a century-old newspaper hoax might still claim. See the Kincaid/Egyptian cave myth for how that story got started and why the geography it describes doesn’t hold up.

What’s actually off-limits (and why)

Every documented cave and every documented mine in Grand Canyon National Park is closed to casual public entry — full stop — under the compendium’s general rules, with individually named sites (Orphan Mine, Cave of the Domes, Bat Cave, Rampart Cave) carrying their own specific closure language on top. Cave management and permitted access are their own detailed topic; so is the park’s broader catalog of known, researched cave systems. For the general framework behind every closure in the park, not just underground ones, see what’s actually off-limits at the Grand Canyon, and why.

Sources

1. NPS Geodiversity Atlas — Grand Canyon National Park, Arizona — National Park Service
2. Inside the Grand Canyon's Longest Known Cave — Grand Canyon Trust
3. Grand Canyon National Park Superintendent's Compendium, effective June 16, 2026 — National Park Service
4. Science for Decision Making on Uranium Mining in Arizona: Orphan Mine — U.S. Geological Survey
5. Bats test positive for possible deadly fungus — Arizona Game & Fish Department
6. Mines as Habitat — Abandoned Mineral Lands, National Park Service
7. To the Batcave — Arizona Highways

Grand Canyon National Park doesn't advertise a number, but the National Park Service has one anyway: 38 documented sites, 75 individual mine features, scattered across a park most visitors think of as scenery, not industrial history. Nobody's mapping them for you — this is what the public record says about how many there are and what the park is doing about it.

The short version

• NPS has formally documented 38 Abandoned Mineral Lands (AML) sites containing 75 individual features — adits, shafts, pits, tunnels, prospects, tailings piles — inside Grand Canyon National Park.
• Twelve of those 38 sites are flagged by NPS as requiring active mitigation.
• Grand Canyon is one small piece of a much bigger federal problem: a 2010-2013 nationwide NPS inventory found 37,050 abandoned mine and oil-and-gas-well features across 133 national park units.
• The park’s Superintendent’s Compendium defines “mine” broadly and closes all of them, park-wide, to public access without special written permission — on top of separate, named closures at specific sites.
• A 2009 ARRA-funded push closed dozens of hardrock features across nine Intermountain Region parks, including Grand Canyon, using bat-gates, grates, backfilling, and fencing.
• No public source found this session breaks the 75 Grand Canyon features down by exact type, or gives a current per-park tally of how many have actually been closed.

Why there are so many holes in a national park

Grand Canyon’s mining history runs from an 1880s copper-and-asbestos prospecting boom through a uranium rush that didn’t wind down until the mid-1980s. Copper, lead, and asbestos were pulled out in relatively small quantities almost from the start. The serious money was uranium, concentrated in a distinctive local geologic feature called a solution-collapse breccia pipe — a vertical column formed where ancient cave systems in the Redwall Limestone collapsed under overlying rock, later filled with metal-bearing groundwater. Breccia pipes are unusual worldwide but abundant across northern Arizona and southern Utah, and often carry both uranium and copper together, plus the occasional mineral found nowhere else — grandviewite, named for the Grand View Mine, is known only from Grand Canyon.

Most of these operations were small and financially marginal, echoing the Bass and Hance mining histories elsewhere on this site. But “marginal” doesn’t mean “gone.” Every adit, shaft, pit, tunnel, prospect, and tailings pile anyone dug still exists somewhere in the canyon, decades or a century after the miners walked away.

Counting the holes: 38 sites, 75 features

The park’s own current figure, published on the NPS Geodiversity Atlas, is specific: 38 documented Abandoned Mineral Lands sites, containing 75 individual features, inside Grand Canyon National Park. Twelve of those sites require active mitigation, per the same source.

That’s the Grand Canyon slice of a much larger federal accounting problem. Between 2010 and 2013, NPS ran its first comprehensive, boots-on-the-ground inventory of abandoned mineral lands across the entire park system, and came back with 37,050 individual abandoned mine and oil-and-gas-well features spread across 133 national park units nationwide. Of that total, roughly 1,800 features had already received long-term remedial action, another 3,800 or so across 76 parks still needed it, and the remaining bulk — over 31,000 — were catalogued for site characterization but required no action. Grand Canyon’s 75 features are a small fraction of that count, but the park is one of the more heavily mined units in the system, given the copper-asbestos-uranium sequence above.

What the public record doesn’t offer, at least in anything found this session, is a type-by-type breakdown of those 75 Grand Canyon features — how many are open shafts versus sealed adits versus surface prospects versus tailings piles. The technical report that almost certainly has that level of detail, Burghardt, Norby, and Pranger’s 2014 NPS comprehensive inventory and assessment, is cited by name on the Geodiversity Atlas page but wasn’t independently opened this session.

What closing a mine actually looks like

The park doesn’t have one universal fix for a hazardous mine opening. The standard toolkit, used region-wide and applicable at Grand Canyon, includes bat-accessible gates and cupolas over adits (horizontal bars spaced wide enough for bats to fly through but too narrow for a person), grates over vertical shafts, fencing, and backfilling. Backfilling isn’t as simple as dumping fill down a hole — where a feature is closed that way, staff document it photographically first, and fill typically stops within three feet of the surface on one side to leave a wildlife ramp rather than sealing the opening flush.

Money for this work has come in uneven pulses. The largest push came in 2009, funded through the American Recovery and Reinvestment Act: $5,006,000 region-wide to fence and sign 144 hardrock features at Saguaro alone and build long-term closures at 85 hardrock features spread across nine Intermountain Region parks together — Black Canyon of the Gunnison, Chiricahua, Coronado, Fort Bowie, Glacier, Glen Canyon, Grand Canyon, Organ Pipe Cactus, and Saguaro — plus reclaiming 13 gravel pits at Great Sand Dunes. That same year, Bat Conservation International separately funded a single $40,000 bat-gate at one adit in Grand Canyon. Neither region-wide total is broken out to show exactly how many closures landed inside Grand Canyon specifically, one of the real gaps in the public record here.

Also in 2009, NPS opened public scoping on an Environmental Assessment to close hazardous mine openings jointly across four parks — Coronado National Memorial, Grand Canyon, Organ Pipe Cactus, and Saguaro — with the same toolkit on the table. NPS’s own framing of the hazards is blunt: falling into shafts, loose rock falling from adit roofs, high radon concentrations, toxic metals, and asbestos inhalation. It also flags something easy to miss: some mine features sit in areas with wilderness character, some serve as important wildlife habitat (bats especially), and some are eligible for the National Register of Historic Places. A hole in the ground can be a hazard, a historic structure, and a bat colony’s home, all three at once — why “just fill it in” isn’t always the answer.

One mine, studied up close

The 38-and-75 figures are useful, but they’re abstractions. A 2003 peer-reviewed NPS Park Science study of the historic Grand View Mine — a copper claim staked by prospector Pete Berry in April 1890 along the still-maintained Grand View Trail, acquired by NPS in 1939 — shows what “AML mitigation” actually involves on the ground. Researchers from Fort Lewis College and New Mexico Highlands University used a portable gamma-ray spectrometer to measure radioactivity in the mine’s waste rock and found levels up to 125 times the local background reading, with the Grand View Trail itself crossing directly over some of the hottest waste-rock piles.

Their recommendations weren’t dramatic: reroute a short trail segment around the worst waste rock, post warning signs, distribute better information to backpackers. As of that 2003 study, the mine’s shafts, entrances, and adits were still open and accessible, and staff relied mainly on backcountry-permit paperwork rather than on-site signage. It’s a small-scale illustration of the same triage happening, in theory, at all 75 documented features: figure out which are genuinely dangerous, and pick a fix that doesn’t erase the history along with the hazard.

What’s actually off-limits (and why)

The park’s Superintendent’s Compendium handles this at two levels. First, a blanket rule: it defines “mine” for management purposes as any anthropogenic feature excavated for mineral extraction — adits, shafts, pits, tunnels, prospects, and tailings piles all count — and then closes public presence, use, and access in every mine meeting that definition, park-wide, without special written permission from the superintendent. The stated reasons are protecting human health and safety, unrecorded archaeological features, and wildlife habitat.

On top of that general rule, the compendium names several closures by site: the Bass Asbestos Mine in Hakatai Canyon (a 500-foot buffer, listed twice), the Orphan Mine’s upper and lower sites (fully fenced), and the Hance Mine (a hard river-corridor closure, Mile 77.5 through 78.6). The compendium also closes the Hopi Salt Mines, a traditional Hopi cultural site along the river — a different kind of place entirely, a sacred salt-gathering location the tribe itself describes, not a hardrock mineral claim, and excluded from the industrial-mining count above out of respect for how the Hopi define its significance.

Beyond those named sites, the other roughly seventy documented features scattered across the park don’t get individual write-ups in the compendium — they fall under the general “all mines” rule instead. For a fuller rundown of what’s closed park-wide and why, see the general off-limits overview.

Sources

1. NPS Geodiversity Atlas — Grand Canyon National Park, Arizona — National Park Service
2. Abandoned mineral lands — NPS Park Science journal — National Park Service
3. Intermountain Region Summary — Abandoned Mineral Lands — National Park Service
4. Abandoned Mine Lands Closure Plan, Project Scoping Newsletter (August 10, 2009) — National Park Service
5. The Legacy of the Grand View Mine, Park Science Vol. 22 No. 1 (Fall 2003) — National Park Service
6. Grand Canyon National Park Superintendent's Compendium, effective June 16, 2026 — National Park Service

John Hance told a lot of tall tales — about grizzly fights, about his own age, about how the canyon got carved. The one thing he didn't exaggerate was how little money his asbestos claims actually made him. Hance ended up more famous as the canyon's first tour guide than as a miner, and the mine that bears his name is now a hard closure on the river, not a tourist stop.

The short version

• John Hance’s mining claims trace to Bill Ashurst’s discovery of the “Wool Claim” near the Colorado River, which became known as the Hance asbestos mine.
• By 1886 Hance had built a trail to those claims at the mouth of Red Canyon, near Sockdolager Rapids — the route that later became the Old Hance Trail.
• The mine itself made him little money; his real income came from selling the asbestos claims outright to Massachusetts investors in 1901 for $6,250.
• Hance is remembered today mainly as the Grand Canyon’s first Anglo tour guide, having led the first documented tour down his own trail in 1884.
• No EPA Superfund site profile for Hance Mine could be found this session, unlike Bass Asbestos Mine and Orphan Mine, which both carry EPA site records.
• The current park rulebook closes the river corridor from Mile 77.5 through the mine itself at Mile 78.6 to all visitation, citing the asbestos hazard.

A miner who became a storyteller

Hance’s own biography is harder to pin down than his trail work. He was born in Tennessee, but sources disagree on the year — a guest-book entry from 1898 implies 1850, while voting records where he listed his own age point closer to 1845-1846. His Civil War service is similarly contested: a contemporary Prescott newspaper claimed he served the Confederacy and was imprisoned by Union forces, but his own niece disputed the story, noting that her father — Hance’s brother George — was an abolitionist. After the war, records place him as a dispatch rider out of Fort Leavenworth in 1865 and later as a “mule skinner” hauling military supplies for a wagon train run by Lorenzo Butler Hickok, Wild Bill Hickok’s brother.

Hance arrived in Prescott, Arizona Territory with his brother George in November 1868. Both settled at Camp Verde, where George ran the sutler’s store and John handled wood and hay contracts for the military post, along with co-owned freight teams. Sometime between 1883 and 1886, Hance relocated to the Grand Canyon’s South Rim and started prospecting alongside other early canyon miners, including William “Bill” Ashurst and Pete Berry.

The asbestos claim and the trail to it

Hance’s mining ventures were never financially successful on their own — the record on that point is consistent. What made his corner of the canyon notable was a claim Ashurst located, the “Wool Claim,” which became known simply as the Hance asbestos mine. By 1886, Hance had completed a trail down to those claims at the mouth of Red Canyon, near Sockdolager Rapids on the Colorado River — a genuinely difficult piece of trail-building through some of the steepest terrain on the South Rim.

That original route, now remembered as the Old Hance Trail, didn’t last. Washouts and rockslides had damaged it badly by the mid-1890s, bad enough that Hance abandoned it outright. Around 1894 he built a replacement — the New Hance Trail, also called the Red Canyon Trail, possibly with help from other miners working the same district. The new route kept moving both ore and tourists: Hance hauled copper and asbestos from his Red Canyon claims over it while continuing to run his guiding business on the side.

A Christmas 1902 photograph shows a line of workers at what’s described as “the Hance asbestos claims on the north side of the Colorado River” — a period snapshot of an operation that, by most accounts, never scaled much beyond that. The real payday came from selling out: in 1901, Hance sold his asbestos claims along the Colorado River to a group of Massachusetts investors for $6,250. That’s a modest sum next to William Bass’s later $25,000 sale of his own claims a quarter-century afterward, but it’s roughly in line with how most Grand Canyon mining actually paid off in this era — not through ore production, but through selling claims to investors who thought they’d be worth more later.

The guide outlasted the miner

Hance and his partners built the earliest wagon road connecting the South Rim to Flagstaff in 1885 — a route that, after a 1960 rebuild and realignment, became today’s Arizona Highway 180. That road-building instinct paid off in a different way than mining ever did. When the railroad reached the South Rim in 1901, Hance moved into Grand Canyon Village, and the Fred Harvey Company put him up with board and lodging in exchange for entertaining tourists with his stories. That arrangement lasted until 1914, when he and the company parted ways. He’d patented his original homestead claim in 1907, and by most tellings he’s remembered today as the canyon’s first tour guide — having led the first documented tour group down his own trail back in 1884, before Grand Canyon was a national monument, let alone a park.

Hance died in 1919. Sources agree on the year; they split slightly on the exact location, with some accounts placing his death in Flagstaff and others simply noting he was near Grand Canyon Village at the end. He’s buried in the Pioneer Cemetery in Grand Canyon Village on the South Rim, not far from the trail he cut through Red Canyon almost four decades earlier.

What’s actually off-limits (and why)

The current Grand Canyon National Park Superintendent’s Compendium closes the river corridor around Hance Mine outright: river right from Mile 77.5 through the mine itself at Mile 78.6 is closed to all visitation, because of the asbestos hazard. That’s a blunter rule than the buffer-zone approach used at the Bass Asbestos Mine, which allows entry with special written permission — the Hance Mine closure has no permission clause in the river regulations section.

The mine also falls under the park’s blanket rule covering every mine within its boundaries, which defines “mine” broadly enough to include adits, shafts, pits, tunnels, prospects, and tailings piles, and bars public presence, use, or access in all of them without special written permission from the superintendent — the same rule that protects Bass Asbestos Mine and Orphan Mine.

What’s missing from the public record, at least as far as this search went, is any EPA Superfund site profile for Hance Mine. Bass Asbestos Mine and Orphan Mine both carry EPA CERCLIS site records (both non-NPL, both archived with no further federal action planned). No comparable EPA record for Hance Mine turned up this session. That doesn’t mean the site is cleaner — asbestos hazard is exactly why the river corridor is closed — it just means the applicable protection here is the NPS compendium’s closure, not a federal Superfund designation. See the park’s general rundown of what’s closed and why for how that compares across sites.

Sources

1. John Hance biographical chapter — Arizona Highways
2. Hance — Sublimity & Spectacle, Grand Canyon 100 exhibit, Northern Arizona University Cline Library
3. New Hance Trail — Grand Canyon Historical Society
4. Mining — Nature, Culture and History at the Grand Canyon (Grand Canyon Historical Society)
5. John Hance: From Miner to Mythmaker — Hatch River Expeditions
6. Mile by Mile: Hance Rapid — Western River Expeditions
7. Grand Canyon National Park Superintendent's Compendium, effective June 16, 2026 — National Park Service

A hole in the rock is not just a hole in the rock. Grand Canyon National Park runs two entirely separate legal categories for the things underground — cave and mine — and which one applies decides who can get a permit, what the closure paperwork says, and whether the thing that killed the last person who wandered in was a rockfall or a fungus.

The short version

• Federal law defines “cave” as a naturally occurring void — and specifically excludes mines, tunnels, and other manmade excavations from that definition.
• Grand Canyon’s own management rules go further, requiring a natural opening to be at least 50 feet long and narrower than it is deep to count as a cave at all — which is why Redwall Cavern, a giant natural amphitheater every river trip stops at, officially isn’t one.
• “Mine” gets its own management definition: any human-made excavation for mineral extraction, covering everything from a hand-dug prospect pit to a 1,500-foot uranium shaft.
• Both categories are closed to the public by nearly identical rules — but for different stated reasons, safety and archaeology for mines, safety, archaeology, and biology for caves.
• Nobody has a precise count of either. NPS estimates the park may hold as many as 2,500 caves with several hundred documented (a more recent inventory effort puts documented caves over 660); no equivalent official total exists for mine features.
• The two categories overlap more than the rulebook suggests — abandoned mine shafts are now serious bat habitat, so a “mine” closure and a “cave” closure can end up protecting the same thing.

What actually separates a cave from a mine

The starting point is federal, not local. The Federal Cave Resource Protection Act of 1988 defines a cave as:

“Any naturally occurring void, cavity, recess, or system of interconnected passages which occurs beneath the surface of the earth or within a cliff or ledge (including any cave resource therein, but not including any vug, mine, tunnel, aqueduct, or other manmade excavation) and which is large enough to permit an individual to enter, whether or not the entrance is naturally formed or manmade.”

Read that middle clause again: the federal definition of “cave” explicitly carves mines back out. A hand-dug adit and a water-carved passage can look identical from the entrance, sit twenty feet apart in the same cliff face, and belong to two different legal universes.

Grand Canyon’s Superintendent’s Compendium — the park’s current rulebook, effective June 16, 2026 — adds a park-specific wrinkle on top of the federal definition: for management purposes, any dissolution or erosion feature counts as a cave only if it’s at least 50 feet long and its entrance is no wider than the feature is long. The compendium supplies its own counterexample: “Redwall Cavern is not a cave by definition” — the famous, room-sized overhang on the river corridor fails the test because its opening is wider than it is deep. It’s a natural feature, a genuinely spectacular one, and administratively not a cave at all.

“Mine” gets the opposite treatment — deliberately broad. The compendium defines it as “any anthropogenic feature excavated for the purpose of mineral extraction,” and spells out that this catches adits, shafts, pits, tunnels, prospects, and tailings piles alike. A single test hole scraped out by a prospector in 1891 who never found anything counts exactly the same as the Orphan Mine’s 1,500-foot uranium shaft. Origin of the hole, not its size or history, is what the definition turns on.

How the two get closed — and why the reasons differ

Once something is legally a mine or a cave, the closure language is almost a mirror image. All mines in the park are off-limits to the public except for people with written superintendent permission for research or administrative work, justified by “human health and safety, unrecorded features, archaeological resources, and wildlife habitat.” All caves require a valid entry permit, justified by protecting “the many unrecorded features, archaeological resources, and various life that may reside in the thousands of Grand Canyon caves.”

Read closely, the mine rule leads with safety — shafts collapse, ladders rot, old timber gives way — while the cave rule leads with biology and archaeology on top of the same safety concerns. That’s not boilerplate. Individual named sites get their own, more specific closures layered over the general rule. The Orphan Mine’s fence line cites “open shafts, sharp metal, and varying levels of radioactivity” — a hazard list that reads like a mine, because it is one. Cave of the Domes, by contrast, is closed specifically “to protect bats residing within the cave” and to stop humans from carrying in the fungus that causes white-nose syndrome — a biological rationale that has nothing to do with mining and everything to do with what lives there. Two named river-corridor caves get their own one-line bans layered on top of the general permit rule: Bat Cave and Rampart Cave. Rampart Cave’s closure has a specific history behind it — it held one of the most significant Shasta ground sloth dung deposits in North America, studied by Smithsonian researchers since the 1930s, until vandals broke its protective gate in 1976 and started a fire that burned through 70% of the deposit.

What the inventories actually say

Here’s where the record gets honestly thin. NPS’s own Geodiversity Atlas for the park states that almost all of Grand Canyon — 97% — sits on karst terrain, more than any National Park Service unit except the Everglades, with the Redwall Limestone hosting most of the caves. From that geology, the Atlas estimates the park “may contain as many as 2,500 caves with several hundred caves having been documented.” A more recent, narrower figure comes from ongoing NPS-permitted cave inventory fieldwork reported by Arizona Highways magazine in 2024: “the park has documented more than 660 caves.” Both numbers come from legitimate NPS-linked sourcing; they simply reflect different points in an inventory that is still actively growing. That growth is real and recent — a cave system found in 2007-2008 by permitted caver Jason Ballensky has since been mapped past 40 miles of passage, making it one of the longest known caves in the world, and it’s still not fully explored. It also holds a scientifically significant deposit of naturally mummified bats, a find covered in more depth in the bats and white-nose syndrome piece.

Nothing comparable exists on the mine side. The definitive published inventory — George Billingsley, Earle Spamer, and Dove Menkes’s 1997 monograph Quest for the Pillar of Gold: The Mines & Miners of the Grand Canyon — documents the canyon’s mining history site by site, but no total feature count from it turned up in this research. What the historical record does make clear is the shape of the mining era rather than its raw numbers: prospectors organized roughly nine mining districts in and around the canyon in the 1870s-80s, under rules that capped claims at 20 acres but placed no limit on how many claims one person could hold. Across about 40 years of that free-for-all, “hundreds of prospectors and dozens of miners worked tirelessly,” and by one careful historian’s count, fewer than half a dozen copper and asbestos mines plus a single uranium mine ever turned a real profit. The rest were often filed to tie up scenic real estate rather than to dig it — “many of them merely speculative and some downright bogus,” as Grand Canyon Historical Society’s account puts it. Nationally, NPS’s Abandoned Mineral Lands program has tallied roughly 38,000 hazardous mine features across the whole park system, but no park-specific figure for Grand Canyon was found this session — a genuine gap, not a rounding error.

Where mines and caves turn out to be the same problem

The two categories aren’t as separate in practice as the rulebook implies. Old mine workings across the National Park System have become de facto bat habitat: of the 45 bat species native to the U.S., 29 use mines for some part of their life cycle, and NPS’s own page on Grand Canyon bats says it plainly — “Before the Grand Canyon was a National Park, it was home to many copper, gold, and uranium mines. Now these abandoned mines make excellent habitat for many bat species.” That means closing a mine and closing a cave can serve the identical biological purpose. NPS’s toolkit for sealing hazardous mine openings — steel gates, cupolas, wire cable netting, earthen backfill — includes “bat gates,” designed to let bats fly freely in and out while keeping people out, and any closure work near bat habitat has to follow the same white-nose syndrome decontamination protocol used in caves (see bats, white-nose syndrome and cave closures).

What’s actually off-limits (and why)

In practice: every mine in the park and every cave in the park are both closed to casual visitors, full stop, under the compendium’s general rules — no exceptions for “just looking,” no informal access even to sites without a name or a fence. What differs is the stated reasoning layered on top for specific sites. Mines close because they’re dangerous and historically significant (the Orphan Mine is the clearest example). Caves close because they’re dangerous, archaeologically sensitive, and biologically irreplaceable — a distinction that matters most for the park’s bat population, covered in full in the companion piece on white-nose syndrome and cave closures. For the bigger picture connecting both categories to the park’s tunnels, shafts, and utility corridors, see Grand Canyon Underground; for the general framework behind every closure in the park, see What’s actually off-limits at the Grand Canyon, and why.

Sources

1. Grand Canyon National Park Superintendent's Compendium, effective June 16, 2026 — National Park Service
2. NPS Geodiversity Atlas — Grand Canyon National Park, Arizona — National Park Service
3. To the Batcave — Arizona Highways
4. Inside the Grand Canyon's Longest Known Cave — Grand Canyon Trust
5. Mining — Nature, Culture and History at the Grand Canyon (Grand Canyon Historical Society, by Michael F. Anderson)
6. Miners — Grand Canyon National Park (National Park Service)
7. Quest for the Pillar of Gold: The Mines & Miners of the Grand Canyon — Open Library / Grand Canyon Association Monograph No. 10
8. Abandoned Mineral Lands — National Park Service
9. Mines as Habitat — Abandoned Mineral Lands, National Park Service
10. AML Closures — Abandoned Mineral Lands, National Park Service
11. Bats — Grand Canyon National Park (National Park Service)
12. Pleistocene Life and Landscapes — Grand Canyon (National Park Service)