Lake Estancia was a prehistoric body of water in the Estancia Valley, in the center of the U.S. state of New Mexico. Mostly fed by creek and groundwater from the Manzano Mountains, the lake had diverse fauna, including cutthroat trout. It appears to have formed when a river system broke up. It reached a maximum water level (highstand) presumably during the Illinoian glaciation and subsequently fluctuated between a desiccated basin and fuller stages. Wind-driven erosion has excavated depressions in the former lakebed that are in part filled with playas (dry lake beds). The lake was one of several pluvial lakes in southwestern North America that developed during the late Pleistocene. Their formation has been variously attributed to decreased temperatures during the ice age and increased precipitation; a shutdown of the thermohaline circulation and the Laurentide Ice Sheet altered atmospheric circulation patterns and increased precipitation in the region. The lake has yielded a good paleoclimatic record. This map shows the shoreline of Lake Estancia at three different periods: early Estancia (1,939 m / 6,362 ft above sea level), late Estancia (1,897 m / 6,224 ft), and "Lake Willard" (1,870 m / 6,135 ft). Present-day populated places, county boundaries and roads are overlaid on the map for identification.Map credit: Tom Fish