Built in 1936 by the Civilian Conservation Corps, Sand Lake's 108-foot observation tower stood at a camp that operated from 1925 through 1939 and housed several hundred men who built many of the dikes, fences, and facilities on the refuge. The tower served as a place to spot fires, watch for poachers, and study large flocks of migrating birds. It has 132 wooden steps, a room at the top measuring seven feet by four feet, and 83 windows on all four sides with 11-inch by 12-inch panes of glass that provide wide views of Sand Lake and the surrounding countryside. Similar towers also stand at Waubay and Lacreek National Wildlife Refuges.