Located about 3 mi southeast of Wolf Trap, this operating gristmill dates from the first decade of the 19th century, although the country store was added in the early 20th century. In addition to the restored gristmill, there are two exhibit rooms inside the miller's home. It offers tours every hour on the hour, with the last tour leaving at 3; educational programs; special events; and occasional outdoor concerts. You can picnic on the grounds, feed the ducks, and learn
about America's technological roots. The Colvin Run Mill General Store originally served the local community and today offers penny candy, freshly ground cornmeal and wheat flour, and various old-fashioned goods. The mill itself usually operates Sunday afternoons from April to October. Call ahead to see if conditions permit grinding.