The Lower Crooked River is a remarkable groundwater-fed stream flowing through vertical basalt canyons in the Deschutes River Valley ecoregion in central Oregon (Pater et al. 1998). The 9-mile section of the river between the Crooked River National Grasslands boundary near Ogden Wayside and river mile (RM) 8 is protected under the National Wild and Scenic Rivers Act (16 U.S.C. 1271-1287) for its outstandingly remarkable scenic, recreational, geologic, hydrologic, wildlife, and botanical values (ORVs), and significant fishery and cultural values. Groundwater springs flow directly out of the canyon walls into the Lower Crooked River and create a unique hydrologic setting for native coldwater fish, such as inland Columbia Basin redband trout (Oncorhynchus mykiss gairdneri). To protect and enhance the ORVs that are the basis for the wild and scenic designation, the Bureau of Land Management (BLM) has identified the need to evaluate, among other conditions, fish presence and habitat use of the Lower Crooked River. The results of this and other studies will provide a scientific basis for communication and cooperation between the BLM, Oregon Water Resources Department, Oregon Department of Fish and Wildlife, and all water users within the basin. These biological studies initiated by the BLM in the region reflect a growing national awareness of the impacts of agricultural and municipal water use on the integrity of freshwater ecosystems.
Biological surveys are needed to better understand the aquatic ecosystem of the Lower Crooked River. This baseline information will be valuable to public land managers whose task is to balance resource use while protecting the unique attributes (e.g., ORVs) of the Lower Crooked River. The habitat requirements of coldwater fishes in this section of stream are of particular interest due to state and federal regulation of water temperature in order to protect and restore fish populations. Historical data on the distribution and abundance of stream fishes in the Lower Crooked River are limited to point observations by fishermen and local biologists because steep canyon walls have limited access to most of the river.
Surveys of aquatic habitat (channel morphology and substrate composition) have been conducted for the BLM by the Oregon Department of Fish and Wildlife (ODFW) (ODFW 1997), U.S. Forest Service (USFS 2003), and the U.S. Fish and Wildlife Service (USFWS), but fish surveys using electrofishing gear have never been conducted in the isolated 11-mile section of the Crooked River Gorge, and visual observations with mask and snorkel have only been made at isolated point locations where hiking trails provide access to the river (K. Jones, Steve Marx, and Brett Hodgson, ODFW; P. Lickwar, USFWS; pers. comm.). Thus, there is a poor understanding of stream fish presence and distribution throughout Lower Crooked River.
Information on fish assemblages is available for the Deschutes River basin and applies generally to the Lower Crooked River because the two rivers were connected historically (Zimmerman and Ratliff 2003). The construction of dams throughout the Deschutes River basin has eliminated historic runs of salmon and steelhead and prevented migration of bull trout and Pacific lamprey into the Crooked River system. Native fish species expected to occur in the Lower Crooked River include Columbia Basin redband trout (Oncorhynchus mykiss gairdneri), mountain whitefish (Prosopium williamsoni), sculpin (Cottus spp.), two species of dace (Rhinichthys spp.), two species of sucker (Catostomus spp.), northern pikeminnow (Ptychocheilus oregonensis), chiselmouth (Acrocheilus alutaceus), and redside shiner (Richardsonius balteatus). Threespine stickleback (Gasterosteus aculeatus), a species native to western Oregon, also occurs in the basin but is believed to be introduced (D. Markle, Department of Fisheries and Wildlife, Oregon State University, pers. comm.). Extensive stocking of rainbow
Additional publication details
USGS Numbered Series
Longitudinal Patterns of Fish Assemblages, Aquatic Habitat, and Water Temperature in the Lower Crooked River, Oregon