U.S. Route 166
US 166 highlighted in red
Route information
Auxiliary route of US 66
Maintained by KDOT and MoDOT
Length	164.159 mi (264.188 km)
Existed	1926–present
Major junctions
West end	US-81 in South Haven, KS
Major intersections	I-35 / Kansas Turnpike east of South Haven, KS US-77 in Arkansas City, KS K-15 in eastern Cowley County, KS K-99 south of Sedan, KS US-75 north of Caney US-169 in Coffeyville, KS US-59 in Chetopa, KS US-69 west of Baxter Springs, KS US-69 Alt. in Baxter Springs, KS US-400 east of Baxter Springs, KS
East end	I-44 / US 400 near Joplin, MO
Location
Country	United States
States	Kansas, Missouri
Counties	KS: Sumner, Cowley, Chautauqua, Montgomery, Labette, Cherokee MO: Newton
Highway system
United States Numbered Highway System List Special Divided

U.S. Route 166 (US 166) is a 164-mile (264 km) west–east United States highway. This route and US-266 are the only two remaining parts of historic U.S. Route 66 (which was decommissioned in 1985), since US-666 was renumbered to US-491 in 2003.

US-166 meets the old route of US-66, now designated US-69 Alternate, in Baxter Springs in the southeast corner of Kansas.

State	County	Location	mi[1][2]	km	Destinations	Notes
Kansas	Sumner	​	0.000	0.000	US-81  – South Haven, Wellington	Western terminus; road continues as 160th Street South
		​	3.481	5.602	I-35 / Kansas Turnpike  – Wichita, Oklahoma City	Parclo interchange; I-35/Kansas Tpke. exit 4
	Cowley	Arkansas City	20.540	33.056	US-77 south (Summit Street south)  – Ponca City Ok.	West end of US-77 concurrency
			22.993	37.004	US-77 north (Walnut Valley Green Way)  – WinfieldModule:Jct warning: "road" parameter is deprecated	Roundabout; east end of US-77 concurrency; US-77 north serves South Central Kansas Medical Center
		​	40.883	65.795	K-15 north  – Dexter	West end of K-15 concurrency
		​	44.833	72.152	K-15 south  – Shidler Ok.	East end of K-15 concurrency
	Chautauqua	​	66.984	107.800	US-166 Bus. east  – Sedan	Western terminus of US-166 Bus.
		​	71.325	114.786	US-166 Bus. west / K-99  – Sedan, Chautauqua	Eastern terminus of US-166 Bus.
	Montgomery	​	85.579	137.726	US-75 north  – Independence	Trumpet interchange; west end of US-75 concurrency
		​	88.577	142.551	US-75 south (McGee Street)  – Caney	East end of US-75 concurrency
		Coffeyville	106.083	170.724	US-169 south (Walnut Street)  – Nowata Ok.	West end of US-169 concurrency
		​	108.104	173.977	US-169 north  – Chanute	Interchange; east end of US-169 concurrency
	Labette	Edna	120.743	194.317	K-101 north (Delaware Street)  – Edna	Southern terminus of K-101
		Chetopa	135.054	217.348	US-59 north (Xavier Road)	West end of US-59 concurrency
			136.548	219.753	US-59 south (3rd Street)	East end of US-59 concurrency
	Cherokee	​	150.694	242.518	US-69 / K-7  – Columbus, Miami Okla.
		Baxter Springs	156.181	251.349	US-69 Alt. (Military Avenue)	Former US-66
		​	158.017	254.304	US-400 west  – Parsons	West end of US-400 concurrency
		​	161.322	259.623	K-26 north  – Galena	Southern terminus of K-26
			163.223– 0.000	262.682– 0.000	Kansas–Missouri state line
Missouri	Newton	​	0.406– 0.936	0.653– 1.506	US 400 end / I-44  – Tulsa, Springfield	East end of US 400 concurrency; I-44 exit 1; eastern termini of US 166 and US 400
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Concurrency terminus

Route map:

• Media related to U.S. Route 166 at Wikimedia Commons
• Endpoints of US highway 166