Effects of Natural Beaver Dams and Beaver Dam Analogs on Channel Geomorphology, Sediment Deposition, and Fish Populations in the Hoback River Watershed, Wyoming

Interest in process‐based approaches to address degraded stream habitat throughout the western United States has increased over the last two decades, typically focusing on either installation of woody structure or translocating live beaver ( Castor canadensis ) to incised channels with the expectation they will build dams. We compared the effects of man‐made beaver dam analogs (BDAs) and natural beaver dams on stream geomorphology and fish populations in the Hoback River watershed in western Wyoming. In 2020, BDAs were constructed in Muddy Creek and beavers naturally colonized and impounded Coyote Gulch; individual reaches in both streams were evaluated prior to construction with longitudinal profiles, cross sections, and electrofishing. Annual qualitative evaluation of structures occurred from 2021 to 2024. Sediment behind structures accrued in both reaches, but natural beaver dams contained more woody material, were consistently sealed, and impounded longer reaches than BDAs. Additionally, BDAs tended to be undermined with water moving through or under the structure and failing to retain water and sediments upstream between annual maintenance visits. Conversely, active and abandoned beaver dams had water flowing over the dam, retaining water and sediments upstream. Fish populations showed little response to either structure type; cutthroat trout ( Oncorhynchus virginalis ) were not abundant prior to, but disappeared following construction of beaver dams and nongame fishes showed little change in populations. These results contrast previously reported findings with BDAs, but both structure types generally functioned comparably. Understanding context dependency of responses, and the needed timeline to observe improvements following process‐based restoration actions is warranted for similar stream restorations.