 Many rivers in Wyoming flow through narrow rock-walled canyons. These canyons make an excellent location for reservoirs, as you can see from the one behind me. Reservoirs are built for a variety of reasons, ranging from water storage to irrigation allocation and hydroelectricity. These structures affect and alter the river structure, flora, fauna, and ecosystem of the river. The alterations can provide positive and negative impacts depending on the particular species of interest. The water released directly below the reservoirs is sometimes referred to as tailwaters. Many trout species benefit from tailwaters. Due to the specific heat of water, water released is abnormally warmer in the winter. The opposite is true for summer, with abnormally colder water released. Sediments are also trapped within the reservoir, releasing low turbidity making tailwaters ideal habitat for native and non-native trout. Other species, however, do not benefit. Migratory fish species that need to move up and down the river system for breeding and feeding locations become trapped. Bypasses are structures that are built to allow fish passage. While all tailwaters are not productive trout fisheries, there are many opportunities that exist within the state for outdoor enthusiasts. From the University of Wyoming Extension, I'm Brian Sebade, Exploring the Nature of Wyoming.