The Obion River system provides the main above-ground drainage for northwestern Tennessee.
Three of its major forks (North Fork, Middle Fork, and South Fork) flow through Weakley County
on their way to the Mississippi River. The fourth (Rutherford Fork) runs below and to the west
of Weakley County. The South Fork actually defines the southern border of Weakley County, with
land to the south given over to Gibson County in the early 1800's when crossing the river (by
those living below the South Fork) to get to the county seat (to pay taxes, etc) was not as practical.
