lower shorelines. Another channel entering Lake Estancia was Torreon Creek. Debris was transported from the Manzano Mountains into the lake during highstands. Lake deposits and post-lake dunes The lake deposited flint-gray clay and gypsum during its high water level stages. Deposits from lake level rises have been classified as a geological formation, the Dog Lake Formation. During low water level stages, sulfate-rich groundwater formed gypsum, which together with silt constitutes the low-stand deposits. During low water level stages playa deposits and flood sediments accumulated in the dry lake bed, forming among other things the so-called "Estancia Playa Complex". The Estancia Dune Field is a dune field in Estancia Valley. It consists of gypsum dunes, a rare type of dunes. These dunes were generated when the lake dried up and gypsum was blown away by the wind. Wind-driven excavation of the dry lakebed has produced a scarp, lunette dunes, dome-shaped landforms and crescent-shaped ridges. Hydrology The lake was fed by a centripetal pattern of streams and by groundwater, with highstands being fed mainly by streams and low water level stages by groundwater. The Manzano Mountains were its main water source but there were no glaciers in its watershed. The total watershed of Lake Estancia had an area of about , about 22% of which were occupied by the lake during the late Wisconsin glaciation. This is a large proportion of the watershed, a consequence of the high elevation of Lake Estancia which resulted in lower temperatures and thus slower evaporation than lakes at lower elevation. The water ultimately originated from the Pacific Ocean and westerly winds transported it to Lake Estancia. Groundwater discharge buffered the lake against climatic variations. Leakage of groundwater out of the lake may have become significant at high water levels, thus stabilizing various highstands at a similar elevation around when the amount of groundwater leaking out matched that of inflowing water. In particular, water may have leaked along groundwater pathways and the Chupadera Fault southwards into the Tularosa Basin during the Wisconsin glaciation, stabilizing Lake Estancia's water levels at about despite the progressive infilling of the lake basin. The lake was at times hypersaline and at times freshwater. This was confirmed by foraminifera data that disproved an earlier hypothesis that the lake was never freshwater. During the Wisconsin glaciation, lake waters were oligotrophic and reached temperatures of . Strong winds and the shallow depth of the lake