New Mexico US Route 380 begins at an intersection with
Interstate 25 just west of
San Antonio, New Mexico, and travels through town, meeting the old route of
US 85, now
New Mexico State Road 1. It then travels generally east, and marks the northern edge of the
White Sands Missile Range. The road then turns southeast, crossing the
Carrizozo Malpais before reaching
Carrizozo, meeting
U.S. Route 54. The route continues southeast, climbing the
Sacramento Mountains, and going through the town of
Capitan and briefly travelling through the
Lincoln National Forest, before reaching
U.S. Route 70 at
Hondo and becoming concurrent with US 70. These routes continue eastward, next reaching
Roswell, New Mexico. US 380 splits with US 70 in Roswell, then crossing
U.S. Route 285 in Roswell before continuing east across oil-producing areas of the
Llano Estacado of east New Mexico and the Texas
South Plains.
Texas US 380 enters Texas at a crossing with Farm to Market Road 769, travelling generally due east before meeting up with US Route 82 in
Plains. They continue east passing the former locations of Tokio and Gomez before reaching
Brownfield. In Brownfield, it meets US Routes 62 and 385, and all 4 routes coincide for 3 blocks through the center of town before US 380 splits to the east. The route continues due east through Texas South Plains farmland, passing through
Tahoka, before falling off the Llano Estacado and reaching
Post. The highway then meanders east through rural
Garza and
Kent Counties before reaching the ghost town of
Clairemont. The route then travels east, where it meets
Texas State Highway 70, which both then turn northeast until reaching
Jayton, where US 380 takes a sharp turn back to the southeast. The road then travels through several thousand acres of private ranchland in Kent and
Stonewall Counties before reaching
Swenson. The route continues to the southeast, reaching an intersection with US 83, where both continue southeast into the town of
Aspermont. The route continues to the east and northeast through the communities of
Old Glory,
Rule,
Haskell,
Throckmorton, and
Newcastle, before crossing Lake Graham and reaching the city of
Graham. US 380 continues to the east and northeast through
Bryson before reaching an intersection with US Route 281 and
Texas State Highway 114 in
Jacksboro. US 281 departs southward out of town, while US 380 and TX 114 depart east south of Jacksboro, crossing
Lake Bridgeport before reaching the city of
Bridgeport. US 380 then travels due east toward the city of
Decatur. US 380 exits to the east and reaches an intersection with
Interstate 35 on the west end of
Denton where it is known as University Drive. US 380 continues through the city of Denton, intersecting US Route 77 and US 377 near
Texas Woman's University, before continuing east with US 377. The routes cross the very northern edge of
Lake Lewisville before US 377 departs off to the north. US 380 continues east through the town of
Cross Roads and the city of
Little Elm. Then US380 meets the northern terminus of the
Dallas North Tollway in
Frisco, before reaching
McKinney, where it is also known as University Drive. The route then continues east, passing through
Princeton before crossing the northern fringe of
Lake Lavon, and reaching
Farmersville, where it is signed as the
Audie Murphy Parkway. The route again continues east, passing just south of
Floyd, before reaching an intersection with US Route 69 on the far western edge of
Greenville. Both of those routes then follow a loop around the south end of Greenville, before reaching the routes eastern terminus at an intersection with Interstate 30 and US Route 67. ==Special routes==