Starting as
paved road in the far southwestern corner of
Colfax County in the community of Black Lake at the intersection with
Route 434, New Mexico State Road 120 changes into an
unpaved road just before mile marker 3. It travels east around the northern edge of Ocate Mesa and then heads southeast down Manueles Canyon on the northeastern side of Ocate Mesa. Due east of the top of Ocate Mesa it enters
Mora County and heads south-southeast. After mile marker 12, the road continues southeastward passing the unpaved Los Le Febres turnoff on the right (to the west). Just before the town the road turns east and still on the west side of Wagon Mound, it has its only
interchange at its intersection with
I-25 (exit 387). The road then crosses the intercontinental railroad tracks of the
BNSF Railway. Crossing the Canadian River bridge the road enters
Harding County and then heads north-northeast about into the town of
Roy. for to the community of
Yates. later heading due north the road passes into
Union County. After in Union County headed mostly north, but still on section lines, the road terminates at its intersection with
U.S. Route 56 and
U.S. Route 412 east of
Gladstone. A dirt road continues north at that point for a couple of miles into the Don Carlos Hills. ==Major intersections==