The road heads mostly north through the arid sparsely populated desert plains occupied by ranchos.

The highway crosses the Great Continental Divide after approximately 6.2 miles (10.0 km).

Continuing north NM 146 arrives at I-10, crosses it over a 235.9-foot-long (71.9 m) bridge, built in 1958 before reaching its northern terminus at intersection with the westbound ramps on the north side of I-10 and US 70.

A road connecting Hachita to the old US 80 east of Separ first appears on the 1935 map as Route 81.

The segment corresponding to the current NM 146 was paved some time in mid-1950s, while the southern stretch south of Hachita remained "graded".