Why is Oso Flaco Lake located where it is?
Oso Flaco Lake is formed over an abandoned channel of the Santa Maria River. This channel is thought to have been active before the 1860 s, but was abandoned when the channel meandered southward on the valley plain to its current location. Much of the ancient channel filled in with sediment; however, the channel still acts as a conduit for groundwater in the valley alluvium and helps support the lake.
