As I understand it, the Gulf of California used to go up that far, but the Colorado River dammed it off by dumping silt (at least in part from digging
out the Grand Canyon) in the area at the head of the Gulf today. Once it was cut off, the salt water dried up leaving behind a salt pan that is below
sea level (as is the area around the Salton Sea).
Then the Army Corps of Engineers was working on the Colorado River north of the delta a good ways in the 1920s or so, and whatever they did caused the
river to jump its banks and run into that basin for three years or so, filling the Salton Sea. The fresh water dissolved the salt and, voila, instant
salty inland sea.
It has never gotten much in the way of inflow since then so it just concentrated the salt. Now it gets a bunch of ag runoff that puts pesticides and
such in there, leading to various mass bird kills and the like.
jake |