The Old Mill has been awarded the coveted National Register of Historic Places designation by the Federal Department of the Interior. This award was issued not only because of the age of the original building (1924) but also because of its unique construction as one of the very first poured in place solid concrete buildings in central Texas.
The facility was also recognized as having housed the largest wool scouring mill west of the Mississippi operating until 1985. It also produced lanolin and wool hats. For many years it was the area’s largest private employer processing thousands of tons of raw wool and, during WWII, weaving the wool into military blankets which were later sold by JC Penny as Blue Bonnet Blankets. In 1988 the abandoned buildings which were most likely going to be leveled were purchased and gradually turned into the Old Mill Business Park, one of the largest business complexes in Hays County.
Among the many tenants of the business park were EPS Photographic/Virtual Backgrounds, the developer and manufacturer of specialized products for the professional photographic industry worldwide including the Scene Machine. Also born within the Old Mill was Pixel Magic Imaging, the creator of the self-service digital photography systems found today throughout the world. A later version of the original Pixel Magic system is now in every Walgreens. It all started at The Old Mill.
A historical anthology from 1924 to 1985 is on file in the San Marcos Public Library.