A Trip with Returning Rapids to Recreate “La Rue’s Riffle” Photo 100 Years Later

Photos and essay by Eric Balken, Executive Director

A beam of light falls around a spire along a restoring section of Cataract Canyon.

Last week GCI had the opportunity to join a Cataract Canyon trip led by the Returning Rapids Project with the goal of recreating the “La Rue’s Riffle” photo of Emery Kolb in Rapid #31 above Gypsum Canyon 100 years after it was taken. The name of the rapid comes from E.C. La Rue, famed USGS surveyor who took the photo in 1921.

Huntington Digital Library — Public Domain. https://hdl.huntington.org/digital/collection/p16003coll5/id/15278/rec/106

The photo of Kolb rowing rapid #31 is significant because it’s one of the newest sections of rapids emerging amidst the continued drawdown of Lake Powell reservoir. In 2015, the large rocks in the rapid began to emerge, and in 2018 Returning Rapids Project was able to match a photo of the rapid and get a real sense of how close the rapid is to full restoration. It was the “Eureka” moment that inspired the creation of the project and the extensive documentation that’s happened since.

The La Rue photo was taken at 12:25 P.M. on September 21st, 1921. The group’s goal was to get an exact photo match at the exact time — down to the minute — 100 years later.

The crew looks over a pre-dam Les Jones scroll map.

Jian Wang of the USU Center for Colorado River Studies lines up the 1921 photo to be recreated.

Left: Mike Freeman of USGS measuring river elevation at the confluence of the Green and Colorado Rivers. Right: Chris Wilkowske of USGS setting up a digital benchmark.

Another goal of the trip was to install several USGS benchmarks along the river corridor and create a new “river profile”, which will allow a better understanding about the returning rapids in lower Cataract as the river cuts through reservoir sediment.

Left: the new USGS Benchmark at Clearwater Canyon. Right: Mike Freeman running a GPS survey from the brass cap.

In the past couple months, areas around the Colorado Plateau have experienced massive monsoon events, which often result in flash floods in canyons. These flood events are of particular interest in restoration zones below the reservoir’s high-water mark because they are the primary mechanism for moving reservoir sediment out of side canyons and bringing them closer to their natural state.

An overlooking view of Clearwater Canyon, which experienced a substantial flash flood in the past month or two.

Left: The crew hikes up Clearwater Canyon in a newly-scoured section. Right: A waterfall is slowly emerging from the Dominy sediment. How many more flash floods will it take to fully come out?

Further up Clearwater Canyon, the original creek bed can be seen, with walls of Dominy sediment looming on the side.

Box Elder seedling (left) take hold further up canyon and a Cottonwood sapling (right). Given enough time, native trees and other flora are re-inhabiting these canyons.

Mouth of Dark Canyon

The mouth of Dark Canyon experienced a massive flood, widening the entrance by two or possibly three times its previous size.

A photo match further up Dark Canyon from October 2020 (left) and September 2021 (right). A massive amount of sediment was flushed out of the main canyon corridor along with the vegetation growing on it.

By this point you’re probably wondering if the team successfully matched the centennial La Rue photo. To find out, head over to the Returning Rapids website and check out their most recent trip reports to find out.

Mike and Rob DeHoff overlooking La Rue’s Riffle from above.

A sunset over Meander Canyon.