The Santa Fe River is a 75-mile (121 km) river in northern Florida. The watershed of the river is approximately 1,380 square miles (3,574 km2) and spreads across southern Columbia, southern Suwannee, western Bradford, far southern Baker, Union, northern and eastern Gilchrist, and northern Alachua counties. The headwaters of the river are Lake Santa Fe, near Keystone Heights. The Santa Fe River is usually a slow-flowing river. This slow speed, combined with the abundant leaf-drop from nearby trees, especially Bald Cypress, leads to a very dark-brown river due to dissolved tannins.