SR 139' begins in Jefferson County in Strawberry Plains at an intersection with US 11E/SR 34.

The highway travels west for a short distance before crossing into Sevier County.

[1] SR 139 then splits off and goes southeast again to pass under I-40 before entering Kodak.

[2] SR 139 then runs alongside Douglas Lake and passes by its many marinas and lake homes before entering Dandridge and coming to and end at an intersection with SR 92 in downtown.

On July 1, 1983, as part of a statewide takeover of local roads, SR 139 was re-extended onto its original route between the parkway and Douglas Dam, and extended along the old route of SR 66 to Dandridge.