the Sandia Mountains, to the west by the Manzano Mountains, to the south by the Juames Mesa and Chupadera Mesa and to the southeast by the Rattlesnake Hills. The Estancia Basin is near the Rio Grande-Pecos River drainage divide. The central points of the valley contain over sixty playas, which formed within blowouts; the largest is Laguna del Perro and others include Laguna Chica and Laguna Salina. They hold water only briefly and are not remnants of Lake Estancia. The lowermost point of the valley lies at elevation. The lake At its greatest extent, the lake was about by wide and covered the present-day locations of Estancia, McIntosh, Progresso and Willard. The lake may have resembled Lake Tahoe in California, although Lake Tahoe is deeper. Lake Estancia was the easternmost pluvial lake in Southwestern North America. Distinct shoreline landforms in the Estancia Valley occur at various elevations, including bars, beaches, gravel deposits, ridges, scarps, spits, swales, terraces and wave-cut cliffs. A spit protruded northward into a bay on Lake Estancia's eastern shore. On the eastern side of Lake Estancia is a gypsum ridge about high and long, and smaller ridges are found elsewhere. These features are subdivided into an "older", less well developed shoreline at higher elevations and a "younger", better developed shoreline at lower elevations. Most shoreline deposits were formed by the accumulation of material; only in a few places did the lake actively erode pre-existing terrain. Water levels may have reached above sea level during the early Lake Estancia stage, during the late Lake Estancia stage and possibly during the "Lake Willard" stage, a late highstand. At maximum elevation the lake would have covered and been deep, while the Wisconsin-age lake was only deep with an area of and "Lake Willard" may have reached depth and surface area, although the estimated elevation is uncertain. During low water level stages shallow water or marshes covered the floor of Lake Estancia. Beach ridges from a last filling of the lake are found at the eastern edge of the lake floor. Channels of streams reach the higher shorelines and less recognizable channels continue to lower shorelines. Some streams formed estuaries in Lake Estancia and/or were blocked off by partial or complete beach bars. On the western side of the lake, at Manzano Draw and Buffalo Draw there are deposits of deltas; Manzano Draw generated a fan delta on one of the