Devils Lake, also called Lake Hamilton, a commercial reservoir built for power generation, was four miles above the Lake Walk dam on the lower Devils River and sixteen miles northwest of Del Rio in southeastern Val Verde County (at 29°34' N, 100°59' W). Its dam, a limestone masonry structure, was in the main channel of the river, and Rough Canyon fed into the lake from the east. The massive limestone around the lake was sharply dissected. Soils of the area are dark, calcareous stony clays and clay loams that support oak, juniper, grasses, and some mesquite. The lake was completed in December 1928 by Central Power and Light Company and used to generate electricity, as well as for fishing, boating, and swimming. Its capacity was 9,200 acre-feet, and its surface area was 406 acres. After the summer of 1968 Devils Lake and its dam were inundated by Amistad Reservoir.