The route travels through the western portion of Carthage before reaching its eastern terminus at Bus.

[4] This route was not built, and was removed from the state highway system by 1939.

SH 315 was designated on April 1, 1939 on its current route.

[5] When originally constructed, the route between Mount Enterprise and the former community of Shiloh, approximately 5.8 miles to the east, was the first road in the state's Farm to Market system; the extension of this road in April caused the cancellation of SH 215, a highway that followed a similar routing to the current route.

[6][7] This route became part of SH 315 during the 1939 redescription of the state highway system.