A large lake, Lake Cahuilla, existed in the area from about 20,500 to 3,000 years ago and left evidence as wave cut benches on the higher portions of the Salton Buttes. A beach mark outlines the shoreline of ancient Lake Cahuilla where archeologists found rock fish traps and charred remains of razorback sucker and bonytail bones. High water lines suggest the basin has filled many times, creating a lake some 105 miles (170 km) in length and nearly 300 feet (100 m) deep. Its most recent incarnation is evidenced by fish traps found some 30 feet (10 m) below the high-water mark that were estimated to be between 300 and 1,000 years old.