Lake Estancia was a lake formed in the Estancia Valley, central New Mexico, which left various coastal landforms in the valley. The lake was mostly fed by creek and groundwater from the Manzano Mountains, and fluctuated between freshwater stages and saltier stages. The lake had a diverse fauna, including cutthroat trout; they may have reached it during a possible past stage where it was overflowing. Lake Estancia appears to have formed between the Pliocene and Pleistocene, when a previous river system broke up. It reached a maximum water level ("highstand") presumably during the Illinoian glaciation and subsequently fluctuated between fuller stages and a desiccated basin. Around the Last Glacial Maximum (LGM) time interval, several highstands and a low water level state occurred during the "Big Dry" climate interval. Between 16,100 and 14,500 years ago the lake reached its highest stand of the last 30,000 years before drying up again during the Bølling-Allerød climate interval. The lake briefly returned during the Younger Dryas climate interval and eventually desiccated after about 8,500 years ago during the Holocene. 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. History and climatological implications The Estancia Valley became a closed basin at some point during the Pliocene to middle Pleistocene. Previously, the Estancia Valley was occupied by a river that flowed through the Encino Basin into the Pecos River and eventually into the Brazos River. Fault movement was probably responsible for the breakup of this drainage system. Dissolution of the Permian Yeso Formation may have contributed to the subsidence of the basin. The low thickness of lake sediments in the Estancia Valley suggests that the lake began to form only in the middle Pleistocene. Early Lake Estancia, most likely larger than the LGM lake, existed possibly during the Illinoian glaciation and largely dried up in the warm and dry climate of the Sangamonian interglacial. Climate changes recorded in the cave deposits in the Cavenee Caverns northwest of the Lake Estancia basin have been