{{short description|State highway in Texas}} {{Use American English|date=May 2025}} {{Use mdy dates|date=January 2025}} {{Infobox road |state=TX |type=SH |route=166 |maint=TxDOT |map={{maplink|frame=yes|plain=yes|frame-align=center|frame-width=290|frame-height=290|type=line|raw={{Wikipedia:Map data/Wikipedia KML/Texas State Highway 166}}}} |map_custom=yes |map_notes=SH 166 highlighted in red |length_mi=43.089 |length_ref=<ref name="TxDOT">{{TxDOT|SH|166|link=no|accessdate=December 21, 2009}}</ref> |length_round=3 |established=1927<ref name="SB 15">{{cite book|chapter-url=http://texashistory.unt.edu/ark:/67531/metapth16125/m1/678/|series=The Laws of Texas [Volume 25]|title=General and Special Laws of the State of Texas Passed by the Fortieth Legislature at the First Called Session|chapter=Chapter 37: Davis Mountains State Park Highway|editor-last=Gammel|editor-first=Hans Peter Mareus Neilsen|publisher=Gammel's Book Store|location=Austin, Texas|year=1927|pages=110–111|accessdate=August 16, 2013}}</ref> |tourist=Davis Mountains State Park Highway<ref name="TxDOT brochure">{{cite web|url=http://ftp.dot.state.tx.us/pub/txdot-info/trv/fort_davis_brochure.pdf|title=Davis Mountains State Park Highway|publisher=Texas Department of Transportation|date=February 2, 2010|accessdate=August 19, 2013}}</ref> |restrictions=10' maximum width between SH 118 and FM 505<ref name="restrict">{{cite web|url=http://txdmv.gov/motorcarriers/permit-restrictions/item/1752-el-paso-district-permit-restrictions|title=El Paso District Permit Restrictions|publisher=Texas Department of Motor Vehicles|date=April 6, 2011|accessdate=August 19, 2013}}</ref> |direction_a=West |direction_b=East |terminus_a={{jct|state=TX|SH|118}} |junction={{jct|state=TX|RM|505}} |terminus_b={{jct|state=TX|SH|17}} near Fort Davis |counties=Jeff Davis |previous_type=SH |previous_route=165 |next_type=SH |next_route=167 }} thumb|290px|SH 166 near Sawtooth Mountain in western Jeff Davis County|alt=State Highway 166 winds toward Sawtooth Mountain in the distance. Thick growths of shrubs and small trees are along both sides of the road. Sawtooth Mountain has rugged outcrops of rock at its summit giving the mountain its name. Shrubs partially cover the mountains flanks. '''State Highway 166''' ('''SH 166''') runs for {{Convert|43.0|mi|km|1}} from SH 118 near Nunn Hill in northern Jeff Davis County, Texas passing around a major portion of the Davis Mountains before ending at SH 17 about two miles south of Fort Davis. The highway is maintained by the Texas Department of Transportation (TxDOT).
The scenic highway was originally a longer loop around the mountain range and was envisioned in 1927 as a "state park highway" until an actual state park could be established in the area. SH 166 facilitated construction of Davis Mountains State Park and the University of Texas at Austin's McDonald Observatory during the 1930s.
SH 166 is located entirely within Jeff Davis County and forms part of the route linking Fort Davis, the county seat, to Valentine, the county's only incorporated town. The highway link to Valentine is the only highway intersection between the termini of SH 166, and the rural route does not pass through any cities or towns.
==History== In 1923, the Texas Legislature directed the State Parks Board, a predecessor agency to today's Texas Parks and Wildlife Department, to consider the Davis Mountains as the location of a new major destination park. After the parks board was initially unable to acquire appropriations or land donations for a park, the Legislature in 1927 instructed the Texas Highway Department, a TxDOT predecessor, to build the '''Davis Mountains State Park Highway''' on donated right of way. On September 15, 1930, the effects of the Great Depression finally encouraged local landowners to donate land for the proposed park to stimulate the local economy.<ref name="CCCParks">{{cite web|publisher=Texas Parks and Wildlife Department|title=TPWD Park: Davis Mountains State Park|url=http://texascccparks.org/parks/davis-mountains/|work=The Look of Nature: Designing Texas State Parks During the Great Depression|accessdate=December 21, 2009}}</ref> The road had been designated on September 15, 1930, from Fort Davis as far as the Fowlkes Ranch<ref name="TxMap1933">{{cite map|publisher=Texas State Highway Department|title=Official Map of the Highway System of Texas|url=http://www.tsl.state.tx.us/cgi-bin/aris/maps/maplookup.php?mapnum=6188|edition=June 15, 1933|section=M6-7|accessdate=December 21, 2009|archive-date=June 6, 2011|archive-url=https://web.archive.org/web/20110606065938/http://www.tsl.state.tx.us/cgi-bin/aris/maps/maplookup.php?mapnum=6188|url-status=dead}}</ref> enabling construction of nearby McDonald Observatory and Davis Mountains State Park.<ref name="CCCParks"/> On September 23, 1931, a survey was made for the location.<ref>{{cite web |archive-date=January 29, 2018 |date= September 21, 1931 |archive-url=https://web.archive.org/web/20180129010302/https://publicdocs.txdot.gov/minord/MinuteOrderDocLib/003673806.pdf |title=Minutes |website=publicdocs.txdot.gov |publisher=Texas Department of Transportation |access-date=30 April 2023 |language=en-us |url-status=live |url=https://publicdocs.txdot.gov/minord/MinuteOrderDocLib/003673806.pdf}}</ref> On April 24, 1933, '''SH 166 Spur''' to Mount Locke observatory was added.<ref>{{cite web |archive-date=February 3, 2018 |date=April 24, 1933 |archive-url=https://web.archive.org/web/20180203005651/https://publicdocs.txdot.gov/minord/MinuteOrderDocLib/003673827.pdf |title=Minutes |website=publicdocs.txdot.gov |publisher=Texas Department of Transportation |access-date=30 April 2023 |language=en-us |url-status=live |url=https://publicdocs.txdot.gov/minord/MinuteOrderDocLib/003673827.pdf}}</ref>
By 1939, the route had been extended to make a complete loop around the highest portion of the Davis Mountains ending at its point of origin in Fort Davis.<ref name="TxDOT"/> The highway at that time shared the route of SH 17 through Fort Davis<ref>{{TxDOT|SH|17|link=no|accessdate=December 21, 2009}}</ref> and SH 118 was extended over the northern portion of the highway to Kent and over SH 233 (which was cancelled) north of SH 166.<ref>{{TxDOT|SH|118|link=no|accessdate=December 21, 2009}}</ref> '''SH 166 Spur''' was renumbered as Spur 78. On January 24, 1941, the route designation between Fort Davis and Nunn Hill was canceled with that stretch retaining its designation as SH 118.<ref name="TxDOT"/>
==Route description== The road is within Jeff Davis County, and its entire length is part of the '''Davis Mountains Scenic Loop''' along with portions of SH 17 and SH 118.<ref name="CCCParks"/> The route begins at SH 118 near Nunn Hill approximately 19 miles northeast of Fort Davis. Nearly the entire length of the road is through ranch land. The route travels southeast {{Convert|20.1|mi|km|1}} through winding, mountainous canyons until intersecting Ranch to Market Road 505 to U.S. Route 90 and Valentine.<ref name="GoogleMaps">{{Google maps|title=Overview of SH 166|url=https://maps.google.com/maps?saddr=TX-118+%26+TX-166&daddr=30+40+7.90+N+104+14+22.70+W+to:TX-166+%26+Ranch+Road+505+to:TX-166+S+to:TX+166+%26+TX-17&hl=en&sll=30.533998,-104.065041&sspn=0.000494,0.000862&geocode=FWZs1QEdFsfK-SmfakFhhobvhjG8J-6XFXGGfw%3BFT340wEd6W3J-Q%3BFf4d0gEdh_nI-SmzKRlwEZ7vhjFaZUv3nG-4cw%3BFVnp0QEdlhfM-Q%3BFQZS0gEdQlfO-Smvac9w1JTvhjHIQuJXcNvc_w&t=h&mra=ls&z=11|accessdate=October 19, 2013}}</ref> During this portion of its route, the road has narrow lanes and grassy shoulders.
At RM 505, the highway becomes part of the primary route between Valentine and Fort Davis, the only two towns in the county. Past this junction, the route turns eastward, and the roadway improves with paved shoulders and wider lanes for the remaining {{Convert|22.9|mi|km|1}} until its terminus at SH 17 about {{Convert|2|mi|km|0}} south of Fort Davis.<ref name="GoogleMaps"/>
There are no towns along the route. The road's right-of-way is not fenced through many pastures, and loose livestock on the roadway present a hazard to motorists. Much of the route offers views of Baldy Peak atop Mount Livermore, the highest summit in the Davis Mountains.<ref name="TxAlmanac">{{cite web|publisher=Texas State Historical Association|title=Texas' Natural Environment|url=https://texasalmanac.com/topics/environment/environment|work=Texas Almanac 2008-2009|accessdate=July 3, 2018|date=2017-11-19}}</ref>
==Major intersections== {{Jcttop |state=TX |county=Jeff Davis |length_ref=<ref name="GoogleMaps"/> }} {{TXint |location=none |mile=0.0 |road={{jct|state=TX|SH|118|city1=Kent|city2=Fort Davis}} |notes=Western terminus }} {{TXint |location=none |mile=9.7 |place=Sawtooth Mountain picnic table }} {{TXint |location=none |mile=20.1 |road={{jct|state=TX|RM|505|city1=Valentine}} }} {{TXint |location=none |mile=33.8 |place=Point of Rocks roadside park }} {{TXint |location=none |mile=42.9 |road={{jct|state=TX|SH|17|city1=Fort Davis|city2=Marfa}} |notes=Eastern terminus }} {{Jctbtm}}
==See also== *{{Portal-inline|U.S. Roads}} *{{Portal-inline|Texas}}
==References== {{Reflist}}
==External links== {{Attached KML|display=inline,title}} {{OSM relation|1171373|Texas State Highway 166}}
166 Category:Transportation in Jeff Davis County, Texas