What is U.S. Route 166?
{{Infobox road |country=USA |type=US |route=166 |map={{Maplink|frame=yes|plain=yes|frame-align=center|frame-width=290|frame-height=240|frame-lat=37.059|frame-long=-96.006|zoom=7|type=line|raw={{Wikipedia:Map data/Wikipedia KML/U.S. Route 166}}}} |map_custom=yes |map_notes=US&nbsp;166 highlighted in red |maint=[[Kansas Department of Transportation|KDOT]] and [[Missouri Department of Transportation|MoDOT]] |spur_type=US |spur_of=66 |length_mi=164.159 |length_ref= |established=1926 |direction_a=West |terminus_a={{Jct|state=KS|US|81}} in [[South Haven, Kansas|South Haven, KS]] |junction={{plainlist| *{{Jct|state=KS|I|35|KSTP}} east of [[South Haven, Kansas|South Haven, KS]] *{{jct|state=KS|US|77}} in [[Arkansas City, Kansas|Arkansas City, KS]] *{{jct|state=KS|K|15}} in eastern [[Cowley County, Kansas|Cowley County, KS]] *{{jct|state=KS|K|99}} south of [[Sedan, Kansas|Sedan, KS]] *{{jct|state=KS|US|75}} north of [[Caney, Kansas|Caney]] *{{jct|state=KS|US|169}} in [[Coffeyville, Kansas|Coffeyville, KS]] *{{jct|state=KS|US|59}} in [[Chetopa, Kansas|Chetopa, KS]] *{{jct|state=KS|US|69}} west of [[Baxter Springs, Kansas|Baxter Springs, KS]] *{{jct|state=KS|US-Alt|69}} in Baxter Springs, KS *{{jct|state=KS|US|400}} east of Baxter Springs, KS }} |direction_b=East |terminus_b={{Jct|state=MO|I|44|US|400}} near [[Joplin, Missouri|Joplin, MO]] |states=[[Kansas]], [[Missouri]] |counties='''KS:''' [[Sumner County, Kansas|Sumner]], [[Cowley County, Kansas|Cowley]], [[Chautauqua County, Kansas|Chautauqua]], [[Montgomery County, Kansas|Montgomery]], [[Labette County, Kansas|Labette]], [[Cherokee County, Kansas|Cherokee]]<br>'''MO:''' [[Newton County, Missouri|Newton]] |browse= }} '''U.S. Route 166''' ('''US&nbsp;166''') is a {{convert|164|mi|km|adj=on}} west–east [[United States highway]]. This route and [[U.S. Route 266|US-266]] are the only two remaining parts of historic [[U.S. Route 66]] (which was decommissioned in 1985), since [[U.S. Route 666|US-666]] was renumbered to [[U.S. Route 491|US-491]] in 2003. US-166 meets the old