[1] SR 104 begins as a secondary highway in Dyer County on the banks of the Mississippi River.

SR 77/SR 104 pass by Gibson County Airport before entering Milan as N Main Street.

SR 104 splits off from US 45E/SR 43 a short distance later along Ellington Drive as a signed secondary highway.

It then continues southeast through farmland to enter Lexington and pass along the western shore of Beech Lake to come to an intersection and become concurrent with US 412/SR 20 (W Church Street).

The highway continues southeast to cross into Hardin County and come to an end at an intersection with SR 69 at the western edge of Saltillo.