Mono Lake, a large, shallow terminal (no outlet) saline lake formed at least 760,000 years ago. Diversion of water inflows by Los Angeles beginning in 1920's lowered lake levels 30% by 1982, exposing previously submerged calcium carbonate tufa formations and threatening vital migratory bird resting area and food sources. Nearly 2,000,000 waterbirds, including 35 species of shorebirds, use Mono Lake to rest and eat for at least part of the year including second largest nesting population of California gulls. Name "Mono" from "Monachi", a Yokut term for the tribes that lived on both the east and west side of the Sierra Nevada. Mono County, CA.