Eagle Lake is stocked with brown trout annually. There is an abundant yellow perch population. During the most recent survey, approximately 300 yellow perch were collected averaging 10 inches in size. Eagle Lake is one of the more popular black bass fisheries in Essex County.
It is the second largest natural freshwater lake wholly in California. Having no natural surface outlet, Eagle Lake is a closed basin lake with its water levels fluctuating with variations of inflow. Water surface areas have fluctuated between 16,000 to 29,000 acres with a present area of 26,000 acres.
Eagle Lake is well known for its fish and wildlife. Around its shores are located one of the last colonies of nesting osprey and the largest nesting colony of western and eared grebes in the western United States. It is the home of the Eagle Lake Trout which are native only to Eagle Lake.