About north of Stilwell, the highway intersects with US-62 in Westville. From Westville, US-59 heads northward. The highway passes just east of Mission Mountain; north of the mountain, the road begins paralleling a Kansas City Southern railroad line. 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. Delaware, Ottawa, and Craig counties In Delaware County, US-59 enters West Siloam Springs and becomes concurrent with US-412. This junction is only west of the Oklahoma–Arkansas state line. 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. 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. 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. 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. The next highway junction for US-59, the first in Ottawa County, is with SH-125. US-59 turns due west shortly after