By the time European explorers came to the area in the 16^th century, the Salton Basin was completely dry, though just a half a century before it had been some 26 times larger than the size of the current Salton Sea.

Over the decades, the lake continued to rise and fall until the last large infilling occurred in the early 1700s. However, by the time Don Juan Bautista de Anza led the first large European party through what is now known as the Imperial Valley, the Salton Basin was a salt-encrusted mud flat. In the 1800’s the Colorado River flooded the basin several times creating a number of lakes that came and went.

As early as 1815, salt mining began in the area and when the railroad came through the basin, large scale salt mining started in 1884, and the dry lakebed began to be referred to as Salton Sink or the Salton Basin.

In the late 19^th century the California Development Company and its ambitious president, Charles R. Rockwood, determined to make the Imperial Valley into an agricultural oasis in the desert. A series of canals were constructed in 1900 to allow for irrigation and for a few years the river flowed peacefully, regulated by a wooden head gate, and watering the fields of fruits and vegetables. However, the flowing waters contained large amounts of silt, which soon blocked the head gate. To correct this problem, the California Development Company then cut a new channel a few miles south of the Mexican border. Unregulated by U.S. authorities, the new channel crossed an unstable river delta and when the Colorado River waters began to peak from heavy rainfalls and snowmelt in the summer of 1905, the dike broke and the Salton Basin began to fill at an alarming rate.

For two years, the Colorado River flooded the Salton Sink, destroying the town of Salton and the Southern Pacific Railroad siding. The railroad, having substantial business interests in the region, spent some three million dollars to stop the river's flow into the Salton Sink, finally succeeding in 1907. However, a "new” lake body had been created, which was called the Salton Sea.

The large sea, surrounded by desert terrain, was a natural site for fishermen, but without an outlet, the sea became more and more saline as fresh water was pumped out of the lake for irrigation and when the water returned through run-off it included dissolved salts from the soil, pesticides and fertilizer residue. As the saline levels increased, the fresh water fish died and over the years, officials began to experiment with bringing in various species of salt water fish, including salmon, halibut, bonefish, clams, oysters, and more. Unfortunately, these fish also died due to the high saline level.