Many migratory and resident birds inhabit the park, including the plains species of horned lark and meadowlark. Also found on the park are mountain bluebird, black-billed magpie, common raven and a variety of raptors, waterfowl and shorebirds that are all attracted to the reservoir. Three rare bird species observed at the park include the bald eagle, American peregrine falcon and white pelican. If you are a birding enthusiast, check out the Eleven Mile State Park Bird list.
Mule deer, pronghorn antelope, porcupine, badger, black bear and elk may occasionally be observed, while cottontail rabbit, white-tailed jackrabbit, coyote, muskrat and ground squirrels are more frequently observed residents of the park.
Eleven Mile Reservoir is a high quality fishery and anglers are attracted by the cold-water fishing opportunities for cutthroat, rainbow and brown trout, northern pike and Kokanee salmon; yellow perch, small-mouth bass, white and long-nose sucker, creek chub, fathead and brassy minnow, long-nose dace and sand shiner are also present.