US 84 enters New Mexico at Rio Arriba County south of its terminus at US 160. About south of the Colorado–New Mexico state line, US 64 comes from the west and travels concurrently with US 84 for the next. Only east of this intersection, the concurrency crosses the Continental Divide at Sargent Pass, elevation above sea level or more than lower than Wolf Creek Pass, the next Continental Divide highway pass to the north. Therefore, only of US 84 is located west of the Continental Divide. About east of the intersection, US 64/US 84 enters the town of Chama. At a T-intersection, New Mexico State Road 17 enters from the north and terminates at said intersection, while US 64/US 84 enter from the south and west. After heading south from Chama, US 64/US 84 combine for about to Tierra Amarilla, where US 64 departs from US 84 and heads southeast, while US 84 continues south. About down the road, US 84 is joined by US 285 south of the small community of Chili. About further, US 84/US 285 enter the city of Española from the north as North Paseo de Onate Street. At the south end of the town, US 84/US 285 becomes the Santa Fe Highway and a four-lane expressway. And about further, US 84/US 285 becomes a limited-access freeway. further south, the two return to surface street status and then travel past downtown Santa Fe via St. Francis Drive. On the south side of Santa Fe at Interstate 25's exit 282A, US 84/US 285 merge with northbound I-25/US 85. All four highways head east and slightly to the south to avoid the Sangre de Cristo Mountains. Just before turning north, US 285 exits the freeway at exit 290 and continues south towards Clines Corners. After winding north and south, the freeway finally begins heading solely north, and US 84 exits about later at exit 339 near Romeroville and travels in an east/southeastern direction, while I-25/US 85 continue north to Colorado. Following a path southeast and then south for, US 84 merges with I-40 at I-40's exit 256. After I-40/US 84 enter Santa Rosa. About from its concurrency with I-40, US 84 diverges at exit 277. The highway then travels south/southeast for until merging with US 60 in downtown Fort Sumner. From the intersection with US 60, US 60/US 84 travel east, passing through Taiban and Melrose before intersecting US 70 after in Clovis. From the intersection with US 70, US 64/US 70/US 84 travels east entering Texico. Here, about before the Texas–New Mexico state line, US 60 splits from US 70/US 84 with US 70/US 84 continuing east into Farwell, Texas. Despite being a west-east route, US-84 is signed as north-south between Fort Sumner and the Colorado border.
History
US 84 was first extended west into New Mexico in 1936 at Texico. In 1937, the route was extended further to Santa Fe, and in 1938, the route was extended further to Cortez, Colorado. However, this extension did not last long, because the highway was truncated back to Santa Fe. The current route for US 84 was created in 1941.
