Eagle Cap Wilderness is home to a variety of wildlife, including black bears, cougars, Rocky Mountain bighorn sheep, and mountain goats. In the summer white-tailed deer, mule deer, and Rocky Mountain elk roam the wilderness. Smaller mammals that inhabit the area year-round include the pika, pine martens, badgers, squirrels, and marmots. Birds include peregrine falcons, bald eagles, golden eagles, ferruginous hawks, and gray-crowned rosy finch. Trout can be found in many of the lakes and streams in the wilderness.