Summary of the late Quaternary geology of Lake Animas, Hidalgo County, New Mexico
— Fleischhauer, Henry L., Jr.

During the late Quaternary, a small lake occupied the Lower Animas Valley west of Lordsburg, New Mexico. This body of water was named Lake Animas by Schwennesen (1918), who first recognized lacustrine shoreline features on piedmont toeslopes surrounding the playas variously known as the Lordsburg Playas, or the North and South Alkali Flats. He identified the lowest shore ridge, which ranges in elevation from 1,269 to 1,276 m (4,165 to 4,185 ft), on the east and west sides of the valley and recognized slightly higher shore features in two areas near the playas. However, Schwennesen (1918, p. 88) postulated a high-stage elevation of 1,338 m (4,390 ft) on the basis of a ridge found near Animas, New Mexico, some 30 km south of the playas. Such a lake would have been over 60 m (200 ft) deep in the Animas Valley and would have extended across the present divide into the valley of the Gila River.

 

Subsequent workers in the Animas Valley have largely con-fined their studies to surrounding mountains, though brief statements have been made regarding Lake Animas. Gillerman (1958) mapped lacustrine shore deposits at elevations slightly below 1,280 m (4,200 ft). Flege (1959) mapped the trace of two shorelines on the east side of the valley. The lower of these was placed below 1,280 m, but the higher was placed at about 1,292 m (4,240 ft). Flege (1959, p. 2) interpreted the latter shoreline as a wave-cut terrace.

 

It is apparent from the existing literature that discrepancies exist regarding the former level and extent of Lake Animas. This study was initiated in an effort to resolve this question as well as questions of age and geologic history of the lake. W. J. Stone, R. H. Weber and J. W. Hawley of the New Mexico Bureau of Mines and Mineral Resources, and J. R. MacMillan of the New Mexico Institute of Mining and Technology provided valuable help during the course of the investigation. Partial financial support was provided by the New Mexico Geo-logical Society and the New Mexico Bureau of Mines. C. V. Haynes, T. L. Smiley and L. D. McFadden of the University of Arizona reviewed the manuscript.