Spring Lake is an artificial lake located in south-central Hays County at the base of the Balcones Escarpment, which marks the boundary between the Edwards Plateau (Hill Country) and the Blackland Prairie. The lake is fed by a large artesian outflow of anywhere from 200 to 3000 springs that emanate from the Edwards Aquifer to form the headwaters of the San Marcos River. Spring Lake was created in 1849 when General Edward Burleson, commander of the First Regiment during the Battle of San Jacinto and an early founder of the City of San Marcos, built a dam across the river about one-half mile downstream from the springs to accommodate a mill.
Beyond its interesting history, Spring Lake is also home to a collection of archaeological sites dating from the present to over 13,000 years old. This time depth has led to the Spring Lake Site (the collection of sites around the lake) being labeled by archaeologists as the longest continuously inhabited location in North America. Why would this one location in Central Texas be so attractive to people over the past 13,000-plus years? Well, this part of Central Texas is where two large-scale environmental provinces come together and it is capable of supporting tremendous fauna and flora (animal and plant) diversity in addition to dense human occupations in the past. Archaeological investigations, terrestrial and underwater, have been conducted intermittently at the Spring Lake Site since the 1970s and this work has produced an increasingly complete picture of the overall extent, nature and timing of prehistoric and proto-historic occupation at this important site.
The current Spring Lake excavation is an extension of a large excavation block that was excavated during Texas State University field schools between 2001 and 2006. These field school excavations were considered necessary to mitigate the loss of information anticipated from unavoidable impacts associated with the proposed construction of the Texas Rivers Center. Recovered lithic material included ground stone, modified flakes, bifaces, cores, core tools, unifaces, and projectile points. Based on the recovery of chronologically diagnostic materials, earliest deposits occurred during the Early Archaic period, though the depth of this cultural period is unknown because the excavations ended before reaching the bottom of the component. Over 19,000 fragments of faunal remains, 121 pieces of shell, and 29 ceramic sherds were collected during the field schools, with the Middle Archaic being by far the best represented cultural period in the block.
Because of discoveries at several different locations around Spring Lake since 2010, researchers at CAS have become interested in a particular, small period of time at the end of the Early Archaic called Calf Creek which occurred about 5750 to 6000 years ago. During this brief interval of time, the environment in the Spring Lake area changed in a way that encouraged bison (buffalo) to come into the area. As a result, bison hunting became an important part of the way the people living in this area collected food. Very little is known about this period. Although Calf Creek represents a relatively short span of time, it is easily identifiable by the presence of large and distinctive Bell and Andice dart points.
The current excavation began in June of this year, under the direction of Dr. Todd Ahlman. The project’s goal is to excavate 40 cubic meters (about 1,412 cubic feet) of archaeological sediment, analyze the recovered materials, and make the results available to both researchers and the general public. The original field school block has been reopened, and new units have been opened along its south west wall.
The archaeologists working at Spring Lake today are interested finding answers to three broad questions:
1. What kinds of people lived at this location, and when?
2. What kind of environment did they live in, and how did it change over time?
3. And especially, how can we better define of the Calf Creek horizon at Spring Lake: what kinds of tools did people use for hunting these much larger animals, how did the way they lived change, and how can archaeologists learn to see and understand these changes in the artifacts left behind?
In the next part of this post, student archaeologist Amanda Castaneda will present the work she has been doing to document the stratigraphy (the layers of soil) at the Spring Lake Data Recovery.
edited 9/24/2014; thanks to Chris Dayton for correcting our math.