Lake Clark National Park and Preserve is home to several species of big game. Black bears are present throughout the park and preserve except at higher elevations. Brown (grizzly) bears are common in all habitats, but Chinitna Bay, along the coast, supports the most sizable concentration. Caribou remain primarily in the hills around Turquoise, Twin and Snipe lakes and westward to the Bonanza hills. The population of the herd is estimated to be over 200,000 animals, and is increasing in size. Moose, the largest members of the Deer family, are found below timberline throughout the park.
Dall Sheep are the northernmost species of wild sheep in North America. These white sheep number about 600 animals and range at higher elevations all along the western flank of the Chigmit Mountains. Lake Clark is also home to many less conspicuous mammals. Coyotes are found in grassy as well as brushy or boulder-strewn areas of the park. Wolves are mainly in the park's mountainous areas, generally below 5,000 feet in coniferous forests, and in open tundra. Both red fox and lynx are found throughout the park at almost any elevation, primarily in coniferous-hardwood forests and open tundra.
Other fur-bearers found in Lake Clark National Park and Preserve include marten, river otter, wolverine, weasels, mink, hares, porcupine, and beaver. Though the park does not encompass a marine environment of great size, both Chinitna Bay and Tuxedni Bay support a variety of marine mammals. Some of these mammals include sea lions, beluga whales, harbor seals and porpoises. Other whales may also be seen occasionally in the area. Most of the coast freezes in the winter, and therefore does not support a year-round marine mammal population.