U.S. Route 90
U.S. Route 90 (US 90) is an east–west United States highway. Despite the "0" in its route number, US 90 never was a full coast-to-coast route; it has always ended at Van Horn, Texas with the exception of a short-lived northward extension to US 62/US 180 near Pine Springs, Texas which lasted less than a year, and the signs on that segment were changed to Texas State Highway 54, traveling from Interstate 10 (I-10) at exit 140A and heading to its northern terminus at US 62/US 180.
Tennessee State Route 90
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 Eagan and Clairfield. It comes to an end at Kentucky Route 74 at the Kentucky state line in the old mining community of Pruden. KY 74 continues eastward through rugged mountain terrain to Middlesboro, Kentucky.