Heading into the Oklahoma Panhandle, the three conjoined routes pick up a fourth two miles (3 km) southwest of Boise City, as US-385 merges from the south. In Boise City, US-385 departs to the north along with U.S. 287, which replaces US-385 in the four-way concurrency on the way out of town to the east, before departing itself to the southeast two miles (3 km) outside of town. Shortly thereafter, US-56 also departs the route, heading northeast into Kansas, while US-64 and US-412 continue their journey due east toward Guymon.