The Spring Lake Site is so named because it is one of several areas of archeological debris under the lake of the protected property known as Aquarena Springs. Other sites exist all around the lake, which is located in San Marcos in southeastern Hays County. Spring Lake (at 29°53' N, 97°56' W) is produced from San Marcos Springs, which has an average daily flow of 150 to 300 million gallons a day, half a dozen other large outlets from the giant Edwards Aquifer, and a great many small seepages. These combine to form the San Marcos River. The lake lies at the foot of the Edwards Plateau, some thirty miles south of Austin and fifty miles north of San Antonio. Between 9,000 and 10,000 B.C. the Clovis people took up residence at the springs; they were apparently the first people to live there and appear to have located by the springs because of the relative warmth of the water, which is a constant 72° regardless of season. Also, springside trees, grasses and water plants are constantly succulent and could be expected to attract browsers and grazers to the springs as well as to the first few miles of the San Marcos River. Whether the Clovis lived at the site recurrently or permanently, we do not know. The residue of their activity is abundant, especially in flaked stone tools and chipping debris. Huge mammoths, mastodons, and bison were killed away from the main camp with only selected parts, primarily the teeth, brought home. Those fragments had been broken away from the jaw bones with a hammerstone; however, the teeth include interior pulp and dentine. Thus, poor preservation cannot be blamed for the absence of larger bones. By Archaic times bison leg bones and whole teeth appeared in the camp debris. Excavations in Spring Lake were directed by Joel L. Shiner of Southern Methodist University beginning in 1978. The work was sporadic since no significant support was received except from private sources. The Aquarena Corporation, tuition from private underwater classes, and grants from business firms kept the research alive. On the average, small crews were in the water about two days per month. In the 1990s anthropology graduate student Paul Takac continued the archeological research begun by Shiner.
A cultural sequence has been blocked out for 12,000 years of occupation. Following the Clovis people, there was a group that made and discarded large numbers of as yet unnamed long slender lanceolate spear points. These are presumed to date from 7,000 to 9,000 B.C. The two early occupations are followed by the typical Archaic Phases and their distinctive points. About A.D. 1000 the bow and arrow and crude pottery appear. In the 1700s numerous Spanish expeditions passed by but made no permanent settlements. In the 1840s Anglos began settlement. The collecting from the site has been done by scuba divers, because in the late nineteenth century the early Texans dammed the river immediately below the springs and inundated the ancient villages with ten to twelve feet of water. Because of the water, preservation has been excellent. Teeth, wood, and bones already "walked" into the mud at the spring banks have been protected by lake deposition from modern collectors, industry, and roads. In 1994 Aquarena Springs Resort, including Spring Lake, was formally purchased by Southwest Texas State University. The school's Anthropology Department, headed by James Garber, played an increased role in the study of the site and its artifacts. In 1995 the resort featured a new natural history exhibit containing artifacts from the 1978 dig.