Visitors may observe mule deer and occasionally bear, as well as porcupine, red fox, pine squirrel, beaver or muskrat at the park. Over 200 species of migratory and resident birds are known in the park including northern harrier, osprey, great blue herons, western screech-owl, western bluebird, hairy and downy woodpeckers, red-winged blackbird and greater sandhill cranes. The cutthroat trout population at Pearl Lake is designated as Gold Medal. Brook trout, brown trout and grayling are occasionally reported.

Bird, plant and wildlife guides are available at the park book store or on Pearl Lake State Park's iNaturalist app observations for Android and iPhone. iNaturalist is a free online social network and citizen science platform that allows users to record and share observations of biodiversity. By uploading photos or sounds of wild organisms, you can get help identifying species from a global community of naturalists and even an automated identification tool. Using iNaturalist helps you learn about local nature, connect with other enthusiasts, and most importantly, contribute valuable scientific data to biodiversity research and conservation efforts worldwide.