The Panhandle U.S. Route 64 crosses the New Mexico–Oklahoma state line northeast of
Clayton, New Mexico,
concurrent with
US-56 and
US-412. The three highways enter the state just north of the extreme southwest corner of
Cimarron County, the westernmost tip of the
Oklahoma Panhandle. The highways head northeast, passing through disconnected parcels of the
Rita Blanca National Grassland. The first town US-56, US-64, and US-412 encounter in Oklahoma is unincorporated
Felt, of which they skirt the northern edge. The highways then cross the
Beaver River before intersecting
US-385, which joins the other three highways in a concurrency as they approach
Boise City, the county seat. In Boise City, the highways reach a traffic circle which surrounds the
Cimarron County Courthouse. At this traffic circle, US-56, US-64, and US-412 all turn east, while US-385 splits away to the north.
State Highway 3 (SH-3) enters the circle from the north and leaves from the east, following US-64, while
SH-325 begins at the circle and heads west toward
Kenton. East of town, US-56/US-64/US-412/SH-3 have an interchange with
US-287, which bypasses Boise City to the east. northeast of here, US-56 splits away from the other highways; it continues northeast, while US-64/US-412/SH-3 turn onto a due east course. The routes intersect
SH-171 east of the split. Approximately east of the SH-171 junction, US-64/US-412/SH-3 cross into
Texas County. east of the county line, at unincorporated
Four Corners,
SH-95 joins the concurrency; it splits away after following the other three routes for . east of Gate, the highway crosses the Beaver–
Harper county line, the eastern boundary of the Oklahoma Pandhandle, and enters the main body of the state. The two highways proceed into the Woods County seat,
Alva, where they join
US-281. This concurrency lasts about before US-281 splits off to the north on the east side of town; at this point, SH-14 ends. Upon leaving Alfalfa County, US-64 passes into
Grant County. The first town the highway passes through in Grant County is
Nash, where it begins a concurrency with
SH-132. This concurrency lasts for before SH-132 splits away. east of this junction, US-64 intersects
US-60 and
US-81 in a T junction. US-81 northbound and US-60 eastbound continue straight, while US-64 eastbound turns south along with southbound US-81 and westbound US-60 (creating a
wrong-way concurrency with US-60). The three highways continue south into
Garfield County. south of the T junction, US-60 / US-64 / US-81 serve as the eastern terminus of
SH-45. This junction marks the highways' entry into the
Enid area. The highways serve as the city limit boundary between Enid (to the west) and
North Enid (to the east). About south of the SH-45 junction, US-64 splits away from the other two highways at an interchange where US-64 continues south and US-60 / US-81 take a southwesterly tack. US-64 heads south from the interchange on North 4th Street. At Willow Road, US-64 turns due east; it follows Willow Road for about before turning south on North 30th Street. This street has a
parclo interchange with
Owen K. Garriott Road, which carries
US-412; here, US-64 joins US-412, and the two highways head due east out of Enid as a four-lane expressway. About into Pawnee County, US-64 enters the county seat,
Pawnee. Here, the route begins a concurrency with
SH-18. The two highways head southeast out of town together for just over before SH-18 splits off to the south toward
Lone Chimney. US-64 continues alone to the east for about before beginning another concurrency, this time with
SH-99, on the outskirts of
Cleveland. The two highways leave Cleveland, proceeding east through unincorporated territory, before re-entering the city. Here, the two highways head in separate directions, with SH-99 heading north and US-64 heading southeast. This portion of the highway runs parallel to
Keystone Lake, a reservoir formed by the impounded
Arkansas River. US-64 intersects with
SH-48 at the latter's northern terminus before merging with US-412 in a partial interchange (the missing movements are provided via SH-48). This interchange is also the Cimarron Turnpike's eastern endpoint. The freeway turns southeast, briefly entering Westport before crossing Lake Keystone into
Osage County. US-64 and US-412 run through Osage County for just under , cutting across a corner of the county before entering
Tulsa County. Upon entering Tulsa County, US-64 / US-412 serve as the northern terminus of
SH-151. The freeway passes through an outlying parcel of
Sand Springs, running parallel to the Arkansas River, before emerging into unincorporated territory. Proceeding east, the freeways re-enter Sand Springs, passing through an interchange with
SH-97 just south of downtown.
SH-51 joins the Keystone Expressway at this interchange. The freeway then enters
Tulsa (estimated population 394,098 ), the second-largest city in Oklahoma. The Keystone Expressway continues to an interchange at the northwest corner of the Inner Dispersal Loop (IDL), a ring of freeways encircling
downtown Tulsa. At this interchange, US-64 meets
I-244 and the
L.L. Tisdale Parkway. US-412 follows I-244 east, while US-64 and SH-51 turn south along I-244 westbound. The three highways then run along the western side of the IDL. At the southwest corner of the loop lies an interchange serving as the western terminus of unsigned
I-444. US-64 and SH-51 split away from I-244 at this interchange to join I-444 and
US-75. I-444, US-64, US-75, and SH-51 head east along the south leg of the IDL. At the southeast corner of the IDL, the highways part ways; I-444 and US-75 turn north along the east side of the IDL, while US-64 and SH-51 split off to the east. From here, US-64 proceeds south on Memorial Drive into
Bixby. In Bixby, the highway crosses the Arkansas River for the second time. The final county US-64 passes through on its trek through Oklahoma is
Sequoyah County, where much of its path loosely follows that of I-40. SH-100 splits away from US-64 at an intersection about east of the Muskogee–Sequoyah county line, in
Gore. At this same intersection, US-64 is joined by
SH-10, which follows it out of Gore before splitting off southeast of town. US-64 continues alone to the town of
Vian, where it intersects
SH-82. East of Vian, US-64 serves the county seat,
Sallisaw, where it overlaps
US-59. On the southeast side of the city, it comes to an interchange with I-40 (exit 311 from the Interstate). US-64 heast southeast from Sallisaw, turning back to the east at the eastern terminus of
SH-141. It crosses under I-40 just east of here, although there are no ramps between the two roads. US-64 then enters
Muldrow. Here, the highway intersects SH-64B. US-64 then continues into
Roland, where another interchange with I-40 (exit 325) is located. The highway then turns southeast, passing north of
Moffett, with two interchanges serving SH-64D, which heads north to
Dora, Arkansas, and Grand Boulevard, which heads south into Moffett. US-64 then crosses the Arkansas River a fourth time, the final crossing in Oklahoma; the river's east bank is the Oklahoma–Arkansas state line. ==History==