A research article by Cari Johnson et al was recently published in The Sedimentary Record journal on science conducted in Waterhole Canyon on the deposition and erosion of sediment from Lake Powell reservoir. GCI is grateful to have lent a hand in some of the field work with this team and the Returning Rapids Project science trips of 2020 and 2021. Below is a write up a from the first of these research efforts in 2020. Find a summary of the research here.

After a blissful and exciting three days in Meander Canyon and the rapids of Cataract Canyon we had finally arrived at our research basecamp for the Returning Rapids Project Fall 2020 Science Trip. On the way downstream, we had stopped at Imperial and Waterhole Canyons to observe some returning rapids and the sediment banks left behind from Lake Powell. In Waterhole we watched the geologists gawk at the high walls of “the Dominy Formation,” the new geologic sediment layer formed from the long-receded reservoir, cleverly named after former commissioner of Reclamation during the construction of Glen Canyon Dam, Floyd Dominy.

At Waterhole, the group wandered past the 50-foot sediment walls visible from the river and made its way up the drainage. Here, years of flash-flooding had carved out a channel exposing walls of the tiered stratigraphy of Lake Powell’s annual sediment layers — the perfect cross section for the trip geologists to analyze when, where, and how much sediment was deposited from the reservoir over the years. Jack Schmidt, head of Utah State’s Center for Colorado River Studies, USGS geologist Scott Hynek, and University of Utah geologist Cari Johnson set markers in the walls adapted from tent stakes donated by trip members marking the different layers of sediment their trained eyes saw in the banks of sand.

At the mouth of the canyon I locked eyes with a big horn sheep grazing among the river boulders. When we boated down river to the next camp, I thought that would be last time I explored the short but beautiful Waterhole — that evening I was proven wrong. The geology team who started their survey wanted to return the next day with GPS tools to take exact measurements of the layering they observed. As youngest on the trip I was tasked with helping them make the trek up the banks of the river back to the canyon. I would carry a waterproof suitcase with two state-of-the-art GPS Real Time Kinematic (RTK) rover devices that allow pinpoint elevation readings, and we would get data from the markers left behind. Always being up for an adventure and the occasional suffer fest, I obliged.

In the morning we started our two-mile journey upriver from camp. One of the USGS motorboats ferried us part of the way, then we walked the remaining distance along the cobble river bank. We rock-hopped and zigzagged for a couple hours until midday when we finally made it to the mouth of Waterhole.

We unpacked the survey tripods and the RTK’s and got to work. Cari Johnson collected samples from individual layers while Scott Hynek and I took GPS reference points from each marker. We set up one RTK device on a tripod at the bottom of the wash to collect to baseline elevation, then I followed Scott along the canyon with the “rover” RTK and collected data points he found important. As we catalogued all of the points of interest, we climbed up and down the steep, loose, and at times precarious Dominy layer to position the unit where we needed it. The data collected will help these geologists understand how the sediment was deposited from the reservoir, and how it is eroding away with time. Maneuvering through tumbleweeds and tiers of sediment that would occasionally collapse underfoot, it was like mountaineering in the desert.

After several hours we were exhausted and still had a long walk down to camp. We were dreading this, knowing that the sun would be setting before we got back. I badly needed a river bath to wash off the reservoir dust covering me. About 20 minutes into the hike we heard a sound coming from upstream … a group of five boats flying a Jolly Roger was approaching. I climbed on a rock and started waving. They pulled up and were happy to row us down to camp, saving us an hour or more of scrambling in the dark. After we hopped on their boats they cheerily asked, “Hey do you guys want a beer?”