Once the snow recedes at higher elevations, usually in July and August, Wyoming Game and Fish Department fisheries biologists head to the high country to do alpine lake surveys in the Cloud Peak Wilderness (CPW). The Sheridan Fish Management Region covers the Bighorn Mountains from the hydrographic divide and everything that flows east. There are 110 alpine lakes, and several hundred miles of creeks and streams is this large area. Due to the remoteness and number of lakes, management of alpine lakes, those higher than 8,500 feet in elevation, differ greatly than management of lowland lakes like Lake DeSmet.
Our goal is to sample 10 to 12 lakes every summer, which usually gets the fisheries crew to each lake once every 10 years. Due to the time between surveys, keeping tabs on a particular lake can be tricky, thus management is more generalized. Unlike Lake DeSmet, where the fisheries crew can sample twice a year in order to following fish populations trends and make management decisions based on fish sampling results, alpine lakes are broken down into four management categories: fishless, self-sustainable, stocked every two years and stocked every four years.
Most lakes within the CPW were historically fishless. After the arrival of European settlers and the establishment of railways, trout stocking began in Bighorn Mountain lakes and streams. Many fishless alpine lakes in the West were stocked near the end of the 19th century to develop recreational fisheries. Beginning in the late 1800s, lakes and streams of the Bighorn Mountains were stocked by individual citizens, resort owners and government agencies. Of the 110 lakes on the east side of the hydrographic divide in the CPW, 64 contain at least one fish species and 46 are fishless. Of the 64 lakes with fish, 32 lakes are currently self-sustaining, requiring no regimented stocking. Lakes in this category were stocked at one time, but there is enough spawning habitat (good inlet or outlet creeks) that natural reproduction keeps these fisheries going.
That leaves 32 lakes where fish are stocked. Of the 32 lakes, 14 are stocked on a 2-year rotation. Lakes in this category are closer to trails, receive more angling pressure and generally have unsuitable conditions for any natural reproduction to occur. The remaining 18 lakes are stocked on a 4-year rotation. Lakes on a 4-year rotation are generally “off the beaten path,” generally receive less angling pressure and may have some natural reproduction occurring so stocking is not required quite as often.
Alpine lakes are stocked using a helicopter carrying a specialized tank. The tank has several individual compartments where fish and ice are loaded into. The pilot then flies to the lake scheduled for stocking and, while flying low over the lake, releases the fish destined for that body of water.
Anglers wanting to fish the alpine lakes during the open water season should wait until late June or early July before trying to access these lakes. Many years, the lakes remain ice covered until mid-summer and the trails leading to the lakes can be snow covered making hiking difficult. The Sheridan Fish Management Crew maintains a list of wilderness lakes that details the lake location, the last time a lake was stocked and the size of fish found during the last fish population survey. To ask a question about a specific alpine lake or to obtain a copy of the alpine lakes list, call the Game and Fish Sheridan Regional Office at 307-672-7418.
Andrew Nikirk, Sheridan region fish management biologist.