The Obion River system is the primary surface water drainage system of northwestern Tennessee. The Obion has four major forks, the North Fork, Middle Fork, South Fork and Rutherford Fork (which is named after the town of Rutherford). The confluences of these forks are only a few miles above the mouth of the Obion's discharge into the Mississippi River. For the greater parts of their lengths, the forks exist as separate streams. Obion County, Tennessee, is named after the Obion River.