US-70 enters Oklahoma in
Tillman County, crossing the
Red River from Texas,
concurrent with
US-183. The two routes head north into
Davidson, where they split; US-183 continues north toward the
county seat of
Frederick, while US-70 turns due east. It leaves Davidson, passing south of the
Hackberry Flat Wildlife Management Area. Approximately east of Davidson, the highway serves as the southern terminus of
State Highway 54 (SH-54), which connects US-70 to
Hollister. Continuing east from the SH-54 junction, US-70 next enters
Grandfield, where it begins a concurrency with
SH-36. The two highways proceed east from this junction, leaving Tillman County, US-70 having traveled for within its boundaries. US-70/SH-36 pass into
Cotton County, heading southeast along the southern limit of
Devol, which is served by SH-70B, a spur from US-70. US-70 and SH-36 turn back to the east, coming to a junction about east of Devol, where SH-36 splits away to the south. US-70 then comes to an interchange with
Interstate 44 (I-44). This interchange, I-44 exit 5, is the southern terminus of the
H. E. Bailey Turnpike.
US-277 and
US-281 exit the Interstate at this point, forming a triple concurrency with US-70 as it continues east toward
Randlett. US-70 heads due east on an arrow-straight route for the next across Carter County. About east of the county line, the highway passes through unincorporated
Zaneis, After leaving Carter County, US-70 enters the smallest of Oklahoma's 77 counties,
Marshall County. After crossing the county line, the highway heads due east for , passing through
Oakland and then entering the county seat,
Madill. On the north side of the city, US-70 approaches a T intersection with
US-177 and SH-199; this is the southern terminus of US-177. US-70 turns south, forming a concurrency with SH-199. The two highways head toward downtown Madill, where SH-199 splits off. At the same intersection, US-377/
SH-99 join US-70 as it continues south through Madill, splitting away on the south edge of town. US-70 turns southeast, forming the northern terminus of SH-70F before reaching
Kingston. There, US-70 intersects several highways at their termini—
SH-32, SH-70B (a spur to
Lake Texoma), and SH-70A (a spur to
New Woodville and
McBride). US-70 curves back to the east in Kingston, entering Lake Texoma State Park east of town and crossing the
Washita River arm of the lake, which forms the eastern boundary of Marshall County. The first town US-70 serves in Choctaw County is
Boswell, where it junctions with
SH-109 at that highway's western terminus. US-70 then bisects unincorporated
Unger and
Jasper, as well as the town of
Soper. East of Soper, the route forms a concurrency with
US-271. The two highways come to an interchange with the
Indian Nation Turnpike on the western outskirts of the county seat,
Hugo. This interchange is the southern terminus of the turnpike; US-70 and US-271 merge onto the freeway continuing south from the turnpike, while the road leading into Hugo continues eastward as Jackson Street. Formerly this marked the western terminus of
US-70 BUS and the northern terminus of
US-271 BUS, but these routes were decommissioned in 2019. US-70 and US-271 follow the bypass around the southwestern quadrant of town. On the southern edge of Hugo, the highways intersect F Street (the former southern terminus of US-271 BUS); here, US-271 splits away from US-70 and heads south. This marks the end of the freeway; US-70 continues east as a four-lane divided highway with at-grade intersections. US-70 meets the eastern terminus of Jackson Street (former US-70 BUS) on the eastern outskirts of Hugo. US-70 reaches the state line west of
DeQueen, Arkansas; after crossing the line, it passes into
Sevier County, Arkansas. ==History==