US 285 enters the state of New Mexico from Texas, into Eddy County, NM just south of Loving.

The Pecos River runs adjacent to the vast stretch of highway, yet breaks away in Northern New Mexico, before entering Colorado.

As US 285 traverses north on the eastern plains of New Mexico, it passes through the towns of Carlsbad, Artesia and then Roswell.

The route then traverses the Carson National Forest where US 285 now makes a long climb up to the Colorado Plateau, passing through Ojo Caliente as it ascends to the San Luis Valley.

After crossing US 64, the highway passes through the village of Tres Piedras, New Mexico at the south end of the valley, then proceeds north to the Colorado border near the Rio Grande del Norte National Monument.