Crystal River CRYSTAL RIVER INDIAN MOUNDS 2 mi. NW of Crystal River on U.S. 19-98. a.d. 1000-a.d. 1500. Swift Creek, Weeden Island, Safety Harbor periods. 2 large truncated mounds, 1 conical burial mound, a large irregular-shaped shell-midden ridge, and a small oval-shaped shell-midden mound. Museum. Private-public. N.R. 1970.