Eagle Lake

Eagle Lake is one of the largest alkaline lakes in the State. It has a maximum depth of 18 meters (60 feet) and a pH that varies from 8.4 to 9.6. The lake is the remnant of a Pleistocene lake which presumably, from ichthyological evidence, was connected with the Lahontan system but, as it was higher, was not a part of Lake Lahontan.

The lake appears to have been formed by a landslide on the southeastern edge. Fluctuations in its level occur without regard to rainfall, and during falling periods streams flow from the barrier, indicating the porous nature of the dam characteristic of landslide jumbles. The passages through which the water flows are alternately open and closed.

A number of fish are found in the lake, including the endemic Eagle Lake rainbow trout, Salmo gairdnerii aquilarum (see Pine Creek Area), the only trout capable of surviving in such highly alkaline waters. Other fish include the tui chub, Gila bicolor, which is abundant and competes with the trout for food, Lahontan speckled dace, Rhinichthys osculus robustus, Lahontan redside, Tahoe sucker, Catostomus tahoensis, and the introduced brown bullhead, Ictalurus nebulosus.

The abundant fish populations support great numbers of piscivorous birds including several grebe (see Grebe Nesting Area), Forster's tern, Sterna forsteri, double-crested cormorant, Phalacrocorax auritus, and osprey, Pandion haliaetus (see Osprey Management Area).

Integrity: Of the 80-kilometer (50-mile) shoreline, approximately 6 kilometers (4 miles) are used for campgrounds and marinas; of this 6 kilometers, 2.5 (1.5 miles) are privately owned and have been subdivided. A drainage tunnel was constructed in 1927 to bring water to Willow Creek and Honey Lake Valleys; fortunately this practice was apparently discontinued in 1973.

Use: Research, educational, observational, light recreation. Portions of the lake are closed to recreational use. Additional facilities should be limited.

Ref: Amesbury, Robert, 1971. Eagle Lake, Western Prt. & Publ. Co.
Hinds, Norman, 1952. Evolution of the California Landscape. Calif. Division of Wines Bull. No. 158, San Francisco, p. 158.

July 1976