U.S. Route 59 in Oklahoma

US-59 enters Oklahoma in Le Flore County, in the Ouachita National Forest, at the state line at Fogel, Arkansas. US-270 is concurrent with US-59 as it crosses the line.[3] The two routes head westward from the state line, passing through a valley between Black Fork Mountain and Rich Mountain.[4] The first Oklahoma town the two routes pass through is unincorporated Page.[5] Northwest of town, US-59 and US-270 form the northern terminus of US-259, which heads south towards Longview, Texas and Nacogdoches, Texas crossing I-30 and I-20. After this junction, US-59 and US-270 curve around to the north and pass through the two small hamlets of Zoe and Stapp. US-59 and US-270 head north, paralleling the Black Fork Poteau River as they leave the national forest, into Hodgen. North of Hodgen, the highways cross the main branch of the Poteau River and pass through the Wister Wildlife Management Area.[4] Upon landing on the north bank of the river, US-59 and US-270 curve to the northeast as they enter Heavener, where SH-128 terminates. On the north side of the town, US-270 splits away to the west. US-59 parallels the Kansas City Southern Railroad and passes Heavener Memorial Cemetery. The highway turns to the northwest, passing through Howe, and intersects with SH-83 at its northern terminus.[3] North of this junction, US-59 crosses the Poteau River again.[4]

US-59 heads northward, coming to an interchange with US-271 just north of the Choctaw Country Club in the city of Poteau, county seat of Le Flore County. At this interchange, US-59 exits from the mainline to join US-271; continuing north through the interchange places the motorist on the Poteau Bypass, an unnumbered state highway.[6] US-59 and US-271 proceed through Poteau, coming to an interchange at the southern terminus of SH-112, which is also the northern terminus of the Poteau Bypass. The two concurrent roads head north through the towns of Shady Point and Panama. North of Panama, US-59 and US-271 form the eastern terminus of SH-31. At Sunset Corner, US-59 turns to the west and US-271 turns to the east, ending the concurrency.[4] SH-9 passes straight through this intersection from west to east; upon turning west, US-59 follows SH-9 for five miles (8.0 km), splitting away southeast of Cowlington.[5] Just north of this junction, US-59 widens to a four-lane divided highway. It crosses the Arkansas River on a bridge just downstream of the dam that impounds Robert S. Kerr Reservoir.[3] Upon crossing the river, the highway enters Sequoyah County.[4]

US-59's first highway junction in Sequoyah County is with SH-141 west of Gans, where the latter highway reaches its western terminus. US-59 continues northward, crossing Wildhorse Mountain as well as Little Sallisaw Creek, just upstream of where it empties into Robert S. Kerr Reservoir.[4] The highway then enters the county seat of Sequoyah County, Sallisaw, where it has an interchange with Interstate 40 at Exit 308. North of the interstate, US-59 intersects US-64, turning east to follow the latter route into downtown Sallisaw. US-59 splits away to the north, becoming a two-lane highway.[5] North of town, the highway serves as the western terminus of SH-101. US-59 then passes through unincorporated Brushy. North of Brushy, the highway winds through the Brushy Mountains. The road exits Sequoyah County north of this group of mountains.[4]

The next county US-59 enters is mountainous Adair County. The route continues to follow a winding course as it makes its way northeast to unincorporated Cherry Tree. The highway continues northeast past Cherry Tree, before turning back to a due north course as it makes its way into the county seat of Stilwell.[4] Here, the U.S. route has brief concurrencies with SH-100 and SH-51.[3] US-59 leaves Stilwell, twisting through mountainous terrain alongside Peavine Creek until the stream's mouth at the Baron Fork of the Illinois River. The highway crosses the Baron Fork, then passes west of the unincorporated location of Baron.[4] About twelve miles (19 km) north of Stilwell, the highway intersects with US-62 in Westville.[5] From Westville, US-59 heads northward. The highway passes just east of Mission Mountain;[4] north of the mountain, the road begins paralleling a Kansas City Southern railroad line.[5] In northern Adair County, US-59 serves unincorporated Ballard and the town of Watts, where it runs just west of Lake Frances. North of Watts, the highway crosses the Illinois River and continues northward into Delaware County.[4]

In Delaware County, US-59 enters West Siloam Springs and becomes concurrent with US-412. This junction is only 0.07 miles (0.11 km) west of the Oklahoma–Arkansas state line.[7] The two roads head westward through West Siloam Springs before coming to unincorporated Flint. US-59 and US-412 split here, with US-412 following the Cherokee Turnpike, which begins at this interchange. The eastern terminus of US-412 Alternate is also at this interchange; it becomes concurrent with US-59 as the two routes head west.[5] The two highways enter Kansas, Oklahoma, where they part ways at an intersection with SH-10; US-412 Alternate continues to the east, while US-59 turns north along SH-10. Just north of this intersection lies an interchange with mainline US-412, which is still on the Cherokee Turnpike at this point. US-59 and SH-10 head north out of the town of Kansas, intersecting with SH-116 at its western terminus west of Colcord. As US-59 and SH-10 follow a course with many curves as they approach Eucha Lake, which they bridge the east arm of.[4] In Jay, SH-20 joins the concurrency as US-59 and SH-10 turn east toward downtown Jay. There, the three highways form the southern terminus of SH-127. On the east side of Jay, US-59 and SH-10 turn north, leaving SH-20 as it heads east towards its intersection with Arkansas Highway 43. North of Jay, US-59 and SH-10 intersect with SH-127 again, this time at its northern terminus.[5] US-59 and SH-10 cross over the Honey Creek arm of Grand Lake o' the Cherokees before coming to Grove, where SH-10 turns east and US-59 turns west. As it leaves Grove, US-59 turns northwest, running the length of a peninsula out into the lake. At the end of the peninsula, US-59 crosses the lake yet again, landing on the north shore near Copeland. The highway then passes into Ottawa County.[4]

US-59 and SH-10 in Welch

The next highway junction for US-59, the first in Ottawa County, is with SH-125. US-59 turns due west shortly after this junction, then curves to due north. Just east of Afton, US-59 joins US-60 and US-69, and the three highways head northeast. However, only 0.8 miles (1.3 km) northeast of the junction, US-60 splits off at a cloverleaf interchange which also provides access to I-44, the Will Rogers Turnpike.[3] US-59 and US-69 continue northward to Narcissa, where they are the site of SH-25's eastern terminus. Further north, at Dotyville, US-59 meets SH-10 again, turning west along it, while US-69 heads east along SH-10 toward Miami.[5] US-59 and SH-10 continue west, turning north for one mile (1.6 km) before turning back to the west. Southwest of Dawes, the highways cross into Craig County. The northernmost town that US-59 serves in Oklahoma is Welch.[4] Here, US-59 splits away from SH-10, turning northward along unsigned SH-2, its final stretch in Oklahoma. The highway crosses the Kansas state line 14.53 miles (23.38 km) north of Welch.[8]