In a shallow depression on a high plateau, the lake spreads over nearly 1,000 acres. Fed by large underground springs, its waters are fresh and cool, well stocked with fish of many kinds—cutthroat, Eastern brook, and silver trout; bass, perch, crappie and whitefish. Surrounding it were once small stock and dairy farms, chicken ranches, and patches of scrub timber. There is now a little community surrounding the lake. The name was given by a party of hunters, one of whom found a playing card, an ace of diamonds, in the forest adjoining the lake.