About the Project

The Henry’s Fork of the Green River originates high in Utah’s Uinta Mountains, flowing north into Wyoming before draining into Flaming Gorge Reservoir. The river provides habitat to several species of concern, including Colorado River cutthroat trout, bluehead sucker, and flannelmouth sucker. The Wyoming Game and Fish Department labeled the watershed an Aquatic Crucial Area as part of its Strategic Habitat Plan.

The river also supports the region’s ranching community. To exercise their water rights for growing hay and other uses, local ranchers typically use old- school push-up dams. These are built each spring, with heavy equipment deployed in-stream, pushing river gravel and other materials to form a dam, allowing water to be diverted into irrigation ditches. The work is labor-intensive, sometimes dangerous, and often must be repeated during the growing season. These push-up dams wreak havoc on the river’s fragile ecology, block fish passage, degrade water quality, and lead to bank erosion.

In 2018, Trout Unlimited and its partners worked with the Anderson Ranch to replace a push-up dam with a rock vane structure built in the riverbed that allows fish passage while providing ranchers with reliable, easier to access, and safer management of their irrigation water. Rock vanes use large stones to create a U-shaped structure on the riverbed, pointed upstream. Sediment accumulates behind the vane arms and directs flow to the center of the stream and away from the banks. This raises the river levels slightly, allowing for diversion through headgates into irrigation ditches. The headgates provide easy on-off irrigation flow for the ranchers.

That initial success led to more meetings with ranchers, which in turn led to a project to remove 12 push-up dams from the river between 2023 and 2026. Ranchers get better access to their water, and fish benefit with 47 river miles opened up year-round. Open Rivers funded the development of conceptual designs and cost estimates for all 12 sites, while Trout Unlimited raised most of the implementation funds from federal and state grant programs.