The "old fort" has been utilized as a research facility since it became a high school. Along with being a high school, Fort Lewis was self-sufficient by producing most of the food served in the dining hall. 1915 records show that Fort Lewis had over 200 acres under cultivation and owned small herds of Hereford beef cows, Holstein dairy cows, Oxford and Rambouillet sheep, Duroc-Jersey hogs and Percheron horses.
Agronomy and horticulture research began in 1916. Field crop varieties were standardized, pure seed was produced and distributed, seeds and plants were selected; and forage and pasture plants were studied.
Beef cattle research began in the 1940s as Fort Lewis A & M and Colorado A&M began the most extensive study of the effects of inbreeding in cattle. This project was directed by Dr. H.H. Stonaker until 1967 when it was turned over to Dr. Jim Brinks. Al Denham and David Schafer continued the project in the 1990s.
Research at the Old Fort provided many opportunities for graduate student research projects at Colorado State University. Over 40 M.S. theses and Ph.D. dissertations have been written on data collected at the Old Fort (San Juan Basin Research Center). Over 200 scientific papers and popular articles have been published.
In June 2010, Colorado State University closed the San Juan Basin Research Center at the Hesperus location. Many of the historical records are available in the Agricultural Experiment Station archives.