It serves the communities of Morley, White Oak, Eagan and Clairfield in Tennessee, and Pruden at the Tennessee-Kentucky state line.

[1] SR 90 begins in northern Campbell County at an intersection with U.S. Route 25W (US 25W) in the community of Morley, north of LaFollette and southeast of Jellico.

The route then twists and turns through the Cumberland Mountains of northern Tennessee, climbing through a series of switchback curves to the top of Hickory Hill, where it passes through White Oak.

After descending from this ridge to Tackett Creek, the highway veers northeastward into the Clearfork Valley, where it traverses the communities of Anthras, Eagan, and Clairfield.

KY 74 continues eastward through rugged mountain terrain to Middlesboro, Kentucky.