The park is noted for its numerous lakes including three very large lakes - Waskesiu, Kingsmere and Crean. The water quality is high and fish populations robust, except for lake trout that were commercially fished to near-extinction in Crean Lake in the early 20th century and, in spite of protection, have yet to recover their former numbers. Northern pike, walleye, suckers and lake whitefish are among the most common larger fish. One of Canada's largest white pelican colonies nests in an area closed to public use on Lavallee Lake in the northwest corner of the park, and pelicans, loons, mergansers, ospreys and bald eagles are common in summer. Otters are seen regularly, year round. Winter is an especially good time to find otters as they spend considerable time around patches of open water on the Waskesiu Lake Narrows and the Kingsmere and Waskesiu Rivers.