Mono Lake Facts

AGE
At least one million years old. One of the oldest continuously existing lakes in North America.

SIZE
Area
1941: 86 square miles 13 X 9 miles
1982: 60 square miles 12 X 8 miles

Volume
1941: 4,200,000 acre feet
1982: 2,200,000 acre feet

WATER
Primary water sources: Runoff from Sierra in Mill, Lee Vining, Walker, Parker and Rush Creeks, and groundwater springs.

Contents: Sodium Chloride, Sodium Carbonate, Sodium Sulfate (a chloro-carbonate-sulfate "triple water" lake)

Salinity (% of dissolved solids):
1940: 5.2deg.%
1982: 9.5deg.%
pH 10

BIOLOGY
Primary lake life: algae, brine shrimp and brine flies

Nesting birds: California Gulls (50,000) Migratory species: Wilson's Phalaropes (150,000), Northern Phalaropes (50,000), Eared Grebes (1,000,000) and 79 other waterbird species.

GEOLOGY
Mono Basin: Tectonic basin formed by faulting and downwarping of earth's crust. One to three million years old.

Volcanism: Chain of 30 domes of explosive rhyolite (75% silica) erupting continuously during last 40,000 years, as recently as 640 years ago. Negit Island, Paoha Island and Black Point also of volcanic origin.

Sierra: Rising one thousand feet every million years.