Aucilla River

The Aucilla River begins in Thomas County, Georgia, near Thomasville. It crosses Florida's Big Bend region and empties into the Gulf of Mexico at Apalachee Bay. The river is 89 miles long, drains 747 square miles, and its tributaries include the Little Aucilla and Wacissa rivers. In Florida it forms the eastern border of Jefferson County, separating it from Madison County to the north and Taylor County to the south. It flows across karst. Between U.S. 90 and a point a few miles south of Lamont, it runs through a steep-sided valley with whitewater rapids. Farther south, in the Aucilla River Sinks, it disappears underground and reappears about 30 times between Goose Pasture Road and the mouth of the Wacissa. It comes back to the surface for good at Nutall Rise, below which it becomes wider and brackish and turns tidal around U.S. 98.

Much of the river runs through the 47,622-acre Aucilla Wildlife Management Area and lands of the Suwannee River Water Management District. The district manages most of the public accesses, including the Rock Dam, Herndon's Landing, Old RR Bridge, Reams Landing, Jones Mill Creek and Half Mile Rise sites. Madison County runs the Seven Bridges ramp. Taylor County runs the Aucilla Landing at Nutall Rise and the Mandalay ramp. The river is a state-designated paddling trail and a National Recreation Trail open to motorized and human-powered boats. Its shallows and rocky shoals make the paddling more difficult than on the Wacissa.

In 1851–1856, enslaved laborers dug the Slave Canal to link the Wacissa with the Aucilla below Nutall Rise. About 40 underwater archaeological sites have been found in the river, including the Page–Ladson site.