NM 188's southern terminus is at the road's junction with an exit ramp of Interstate 10 (I-10) and U.S. Route 180 (US 180) in Las Cruces, on the western edge of NMSU campus.

The road first follows I-10 northeasterly for approximately 0.9 miles (1.4 km), intersecting East University Avenue, first, then NM 478.

The road then turns farther north, crossing NM 28, and arrives at its northeastern terminus at the intersection with US 70.

According to available maps, sometime between 1958 and 1962, a US 85 bypass road was constructed through the southwestern side of Las Cruces.

In 1988, the New Mexico Department of Transportation (NMDOT) went through a radical road renumbering program, and US 85 was eliminated from the state designation, instead the original length of the highway was broken into smaller segments.