Mammoth Lake began its life as a bend in an ancient river. As animals fell into the river, their bodies were swept to this area and deposited.
Mammoth Lake was mined for its sand and clay deposits as early as the 1950's. In 2003, an excavator operator named Joe unearthed the remains of an early inhabitant of this area, a Colombian Mammoth. Shortly thereafter, the remains of another Mammoth, along with bison, camels, three toed sloths, and others including  a saber toothed tiger were found. The name, Mammoth Lake, was born!
As the sand played out, the decision was made to turn this large 55 acre pit into the largest scuba specific park in the U.S. Planning meetings were held, and the public became aware of it in 2006. In October 2006, Hydrosports Scuba moved to the shores of Mammoth Lake. The pumps removing water from the pit were turned off on December 29, 2006 and Mammoth Lake began filling.
At present the deepest part of the lake sits around 61'.