Most people think of the Salton Sea as an accident happening at the beginning of the last century. Though the current lake in Imperial County was the result of a break in a canal in 1905, the Colorado River was really just following its natural tendency to fill the Imperial Valley with water, something that has been going on for thousands and thousands of years.
The subsequent natural feature has become known as the Blake Sea, Lake LeConte, and most commonly, as ancient Lake Cahuilla.
No one knows for sure how long ancient Lake Cahuilla was part of the Southern California landscape. Geologists date the ancient shorelines to as early as 26,000 years ago. Archaeologists have evidence of humans living along the lake as far back as 2,500 years ago. The Kumeyaay say the lake may have come and gone, but it has always been a part of the landscape.
The ancient lake was formed by the natural flow of the Colorado River, on occasions when the course of the river altered its path to the Gulf of California, and instead found its way into the Salton Sink, filling what is now Imperial and Coachella valleys with water.
At its largest, Lake Cahuilla was 114 miles long, 33 miles wide and 315 feet deep. This is roughly 2,000 football fields long, 580 football fields wide and one football field deep. The lake’s surface was more than 2,000 square miles, six times the size of the present day Salton Sea.
It would take between 12 to 20 years for the lake to fill. After reaching approximately 40 feet above sea level, the lake would breach and the river would cut its way back to the ocean. It then took about 60 years for the lake to completely recede. The lake filled and receded at least five times between 700-1700 CE.
Living along the shoreline of Lake Cahuilla
Moving between the mountains and the shore of the large inland lake during summers, the Kumeyaay fished with bows and arrows, hooks made from stone or shells and built stone fish traps. For 1,000 years, a vibrant culture developed along the lake’s shorelines.
Organic materials do not survive over long periods of time in the desert. While we know that fiber from reeds growing along the marshy lakeshore, such as cattail and tule, were used for baskets, nets, cords, weapons and houses, it is the ceramics and lithics (stone tools) that have primarily been used to define the archaeological sites associated with the lake.
Bowls, jars and other ceramics were used to cook, carry water and store provisions. Projectile points were used as arrows and knives. A few Paleo-indian tools (large spear or dart points from the first people known to have been in North America by 11,500-11,000 BCE) have been found at archaeology sites associated with Lake Cahuilla.
The most evidence, however, points to a consistent occupation of the shoreline from 900 CE to Spanish contact in 1540 and then once again between 1600 and 1700.
Eating along the shoreline of Lake Cahuilla
Not only did the lake provide fresh drinking water, but it also supported a thriving ecosystem and was a source of abundant and varied foods.
Fish from the Colorado River, most commonly razorback sucker and bonytail chub, were so abundant that stone fish traps, still seen along parts of the lake shore, were regularly built to trap fish along the shorelines. Freshwater mollusks took the place of their oceanic ancestors as a food source while salt water mollusks were brought from the Pacific Ocean to make beads and jewelry and used in trade.
The shores were marshy and full of plants. Vast amounts of cattail, reed and bulrush (or tule) were not only habitats for small animals, but were food and sources of fiber themselves. Honey mesquite and seeds from bulrush and cattail were ground for food while tule was used in building houses.
The lake was a major stop for migrating waterfowl along the Pacific Flyway, just as the Salton Sea is today. American coot (also called mudhens), grebes, geese, ducks, herons and pelicans could all be hunted during this time. As the lake receded, the salinity of the water increased, and while it might have provided a source of salt for preserving foods, it would have also changed the types of fish that could live in it. The salinity killed the mollusks entirely.
Water has always been the most important aspect of life in the Imperial Valley. The issues we deal with today are, in many aspects, very similar to the issues that people dealt with for the last 10,000 years: A changing environment, an increasing population and the relationships of complex societies competing for increasingly limited resources.
The last remnant of the ancient lake was gone by the time Juan Bautista de Anza came through the Imperial Valley in 1774. But its memory lived on in the oral traditions of the Native Americans still living here. An uncontrolled Colorado River will naturally fill everything in the Imperial Valley that is below sea level. All you have to do is wait a thousand years.
Neal V. Hitch is director of the Imperial Valley Desert Museum