Since ranching and agriculture took hold in the valley in the mid-to-late 1800s, much of the water from the Walker River – which drains two major basins of the rugged eastern Sierra Nevada Mountains before meandering through several flat, wide agricultural valleys and into this desert terminal lake – has been diverted to irrigation, to the extent that in some years no water actually reaches the lake. The water level of the lake has declined so drastically (over 150 feet!) that as of a few years ago the lake can no longer support trout due to its high salinity.