Oklahoma State Highway 99
State Highway 99 (SH-99) is a north–south state highway through central Oklahoma. It runs from the Texas state line at Lake Texoma to the Kansas state line near Lake Hulah. It is long. The highway overlaps U.S. Highway 377 (US-377) for over half its length. SH-99 continues as K-99 after crossing the border into Kansas. This road continues for to the Nebraska border, where it becomes Nebraska Highway 99, which lasts an additional . Thus, SH-99 is part of a triple-state highway numbered "99", which lasts a total of . SH-99 began as SH-48, a short highway connecting Ada to Holdenville. This highway was gradually expanded until it became a border-to-border route. In 1938, it was renumbered to match K-99, which was renumbered from K-11 the same day. Route description US-377/SH-99 US-377 crosses Lake Texoma on a bridge from Grayson County, Texas into Marshall County, Oklahoma. This is the southern terminus of SH-99, which will overlap with US-377 all the way to the U.S. Highway's northern terminus in Stroud, a distance of . The highways' first junction in Oklahoma is with SH-32 south of Madill. north of this intersection, US-377/SH-99 serves as the northern terminus for SH-99C, a child route of SH-99. The route then heads into Madill, where it forms a brief concurrency with US-70 and SH-199. US-377/SH-99 heads northeast out of town and enters Johnston County. West of Tishomingo, US-377/SH-99 picks up SH-22, which follows them east to the county seat. The same junction in Tishomingo where SH-22 splits away is also the northern terminus of SH-78. north of Tishomingo, the highway sharess a short concurrency with SH-7. US-377/SH-99 goes without another highway junction, which is with SH-99A, a spur to unincorporated Harden City. The highway interchanges with SH-3, a freeway at this point, near Ahloso. US-377/SH-99 merges onto the freeway, which becomes the Richardson Loop around the west side of Ada. At the southwest corner of the loop, SH-1 joins. further north, an interchange serves as the western terminus of SH-19; also at this interchange, SH-3 splits into SH-3E and SH-3W, the latter of which exits the highway to overlap with SH-19. At the next interchange, SH-1 splits off, and the freeway downgrades to expressway. The highway crosses the Canadian River into Seminole County north of Byng. Just after the bridge, US-377/SH-3E/99 intersects SH-39 and SH-56; this is their eastern and western termini respectively. Near Bowlegs, SH-59 joins the concurrency, splitting off again after . As the road enters Seminole, it has an interchange with US-270, where SH-3E splits off. SH-9 also is accessible by interchange in Seminole. US-377/SH-99 encounters another spur of the latter, SH-99A, in unincorporated Little. The routes then have an interchange at Interstate 40 (I-40), exit 200. US-377/SH-99 crosses over the North Canadian River and cross a panhandle of Pottawatomie County before entering Lincoln County. Just north of the county line, the highway passes through Prague. The route does not encounter another highway for , after which lies the town of Stroud, the