Every rafting trip through Grand Canyon starts at a 150-year-old ferry crossing and, until 1928, would have crossed the river itself in a steel cage on a cable. What replaced that cage — bridges, a streamgage, a river ranger crew — is still the infrastructure the whole 226-mile trip depends on.

The short version

• Lees Ferry, established in the 1870s, is both the official start of Grand Canyon’s river corridor (mile 0) and the site of a USGS streamgage that has measured the Colorado River’s flow since 1921.
• That gauge’s readings are legally load-bearing: Lees Ferry is the dividing point between the Colorado River’s upper and lower basins under the 1922 Colorado River Compact, and the gauge is how the compact’s water-delivery obligations get measured.
• Before 1928, the only way across the river at the bottom of the corridor trails was a privately run steel cage on a cable — Theodore Roosevelt used it in 1913.
• The Kaibab (Black) Suspension Bridge, built in 1928, replaced the cage; its half-ton, 550-foot suspension cables were carried down nine miles of trail and 4,000 feet of elevation on the shoulders of 42 Havasupai tribesmen.
• A second bridge, the Silver Bridge (1965-66), was built downstream specifically to carry the Transcanyon Waterline across the river — and now also carries hikers and the River Trail.
• The August 2026 Bright Angel Canyon flash flood closed both bridges indefinitely and destroyed nearly all the smaller footbridges over Bright Angel Creek, cutting the inner-canyon trail network in ways still being repaired.

Lees Ferry: mile zero, and the gauge that runs the river

Every commercial and private river trip through Grand Canyon launches from the same place: Lees Ferry, defined in the park’s current Colorado River Management Plan as the point where the “Local Area” of the river corridor begins, downstream to Pearce Ferry in Lake Mead National Recreation Area. The name comes from John D. Lee, who settled the spot after fleeing involvement in the 1857 Mountain Meadows Massacre and formally launched a ferry service there in January 1873. Lee was arrested and executed in 1877; his wife Emma ran the ferry two more years before the LDS Church bought it and passed it to the Warren Johnson family. By 1896 a new operator, Jim Emett, had strung a cable across the river to keep boats from washing downstream in high water — the same problem every piece of river infrastructure at this site has had to solve since. The ferry ran more than 55 years before it ended in 1928, when the ferryboat capsized and drowned three men. The first Navajo Bridge opened four miles downstream the following year, and the crossing became obsolete.

What didn’t become obsolete was the site’s value for measuring the river. USGS built a streamgage at Lees Ferry in 1921, choosing the location because it was “readily accessible and strategically located to study the hydrology of the Colorado River drainage basin.” A concrete tower at the base of an old dugway road holds instruments reached by a cableway across the river — USGS staff describe crossing it as a “zipline,” visiting roughly ten times a year for maintenance even though updated equipment now transmits readings hourly. One year after the gauge went in, the seven Colorado River basin states signed the 1922 Colorado River Compact and made Lees Ferry the legal dividing line between the river’s upper and lower basins. That turned a hydrology station into an interstate accounting instrument: the compact’s water-delivery obligations are still measured against what this one gauge records. When Glen Canyon Dam, roughly 15 miles upstream, was completed in 1963, the gauge’s record captured the moment the river below it switched from a wild, seasonally flooding system to a dam-regulated one — releases since 1996 have generally run 8,000-25,000 cubic feet per second, with periodic high-flow experimental releases designed to mimic natural floods and rebuild beaches and sandbars downstream.

Before the bridge, a cage on a wire

Downstream, at the bottom of the corridor’s cross-canyon trails, there was no way across the river at all until an outdoorsman named David Rust built one: a roughly 6-by-10-foot steel cage, strung on a cable, that could carry one mule or several people at a time. Theodore Roosevelt used it in 1913. It worked, but it wasn’t built for volume or for weather — an intermediate, wind-prone bridge went up in 1921 and reportedly capsized in high wind at least once. For anyone moving people, mules, or supplies between the North and South Rim trail systems, the bottom of the canyon remained a genuine bottleneck for the better part of two decades.

Building Black Bridge

That changed starting March 9, 1928, when construction began on what’s now called the Kaibab Suspension Bridge, or Black Bridge, funded by a $48,000 allocation and engineered by NPS Chief Engineer F. A. Kittredge and Construction Engineer John H. Lawrence. The finished span runs 500 feet between its supports with a 440-foot, 5-foot-wide walking surface, built from 67 tons of structural steel and 11,000 field rivets — all of it packed in by mule and human carrier, since there was no road anywhere near the site. For two straight weeks, seven packers, 42 pack animals, and seven saddle animals hauled material down daily; getting the main bridge material and supplies in took roughly three months total. The single hardest piece of that job fell to 42 Havasupai tribesmen, who carried the bridge’s one-ton, 550-foot suspension cables down on their shoulders, walking single file more than nine miles of trail and descending 4,000 feet from the rim to the river. The bridge opened later in 1928, finally giving mules and hikers safe, all-weather passage across the Colorado at the bottom of the corridor — replacing the cage-and-cableway system for good.

Silver Bridge and the pipeline

A second river crossing went up decades later, just downstream of Black Bridge, for a different reason entirely. The Silver Bridge, built in 1965-66, was constructed to carry the Transcanyon Waterline across the Colorado River — federal historic engineering records describe it as carrying “the Pipeline, River Trail, and Phantom Ranch’s 12 kv electric line.” Unlike Black Bridge, it wasn’t built for foot traffic first; hikers and mule trains use it because it’s there, but its origin is utility infrastructure, not trail infrastructure. That dual purpose is exactly what made the August 2026 flood so damaging to both trail access and Phantom Ranch’s basic services at once — the same structure carries people and the water line simultaneously.

Running the river today

The infrastructure at Lees Ferry and the two bridges supports a river corridor that’s actively managed, not just historic. NPS issues roughly 450 noncommercial river permits a year through a weighted lottery for the full 226-mile run from Lees Ferry to Diamond Creek, a trip that typically takes 12 to 25 days. A dedicated NPS River Ranger Crew works the corridor year-round: supporting park science, monitoring resources, cleaning campsites and heavily used beaches, maintaining scout trails around rapids, removing invasive plants, training for swift-water rescue, and educating river runners. Search and rescue is a recurring part of that work — parkwide, NPS responds to roughly 310 SAR incidents a year. Boaters launching at Lees Ferry must also certify their gear is clean, drained, and dry to keep invasive species like quagga mussels out of the river, and evacuation requests from anywhere in the corridor route through river patrols, Lees Ferry, or Phantom Ranch to Park Dispatch.

What’s actually off-limits (and why)

There’s no standing, permanent closure on Lees Ferry or the river corridor’s operational infrastructure itself in the current Superintendent’s Compendium — the gauge, the ranger station, and the launch point are working facilities, not restricted zones, and the compendium’s river-corridor language is mostly about seasonal and administrative rules rather than blanket closures. That changed, at least temporarily, after the August 2026 flood: as of NPS’s most recently updated hiking-conditions page, both the Black Bridge and Silver Bridge spanning the Colorado River are closed, along with Boat Beach except for emergencies and scouting, with no estimated reopening date given. NPS’s September 8, 2026 update on the recovery effort noted river patrol crews were still searching downstream along the Colorado River and adjacent areas for flood debris, alongside search teams working the delta area near Phantom Ranch, while separately confirming the flood had destroyed the water intake and damaged roughly 40% of the old Transcanyon Waterline between Phantom Ranch and the North Rim. Until those bridges reopen, the inner-canyon trail network that’s depended on Black Bridge since 1928 stays broken at exactly the point it was built to fix.

Sources

1. A Century of Watching the Colorado River — U.S. Geological Survey
2. Earth Notes: The Lees Ferry Gauge — KNAU Arizona Public Radio
3. Colorado River Management Plan / Operating Requirements — National Park Service
4. River Ranger Crew — National Park Service
5. Bridgeworthy: Building the Kaibab Suspension Bridge — National Park Service
6. Black Bridge — Grand Canyon Historical Society
7. Silver Bridge, Historic American Engineering Record — Library of Congress
8. Grand Canyon National Park Announces Recovery and Repair Plan Following Flash Flood — National Park Service
9. Key Hiking Messages — National Park Service
10. Lees Ferry — Wikipedia (used for early ownership-chain history only; corroborated by USGS on founding-era dating)