The highway begins in
Sunland Park at the Texas state line, just west of the
Rio Grande river. The road travels from south to north, generally following the flow of the
Rio Grande river. NM 273 starts out as two-lane highway for the first , at which point it widens to four lanes. Shortly after the intersection with
NM 498 (Racetrack Drive), the road becomes a 5-lane highway with a center turning lane. The road travels by residential and commercial areas of the town of Sunland Park, skirting it from the east for the next 4 miles. After NM 273 passes by the campus of
Doña Ana Community College. Continuing in the general northwest direction, the highway passes Riverside Elementary School at a 4-mile mark. After leaving the community of Sunland Park, NM 273 enters the town of
Santa Teresa, passes Santa Teresa Middle School, and turns farther northwest, further deviating from the flow of the Rio Grande. After approximately the road turns north and shortly after intersects
NM 136. After the junction, the road narrows to two lanes and remains a 2-lane highway for the remainder of its journey. NM 273 continues north for about , skirting the fields and pecan orchards of
Mesilla Valley from the west, then turns east. After about one mile, the road turns north, and almost immediately east again, and reaches its northern terminus at intersection with
NM 28. ==History==