State Highway 118 (SH 118) is a state highway in the U.S. state of Texas that runs from Big Bend National Park north to Kent and passes through the towns of Study Butte, Alpine, and Fort Davis. SH 118 is maintained by the Texas Department of Transportation (TxDOT). The road lies entirely within the Trans-Pecos region of Texas. SH 118 is a two-lane road along its length except for a section in Alpine where the route follows the path of U.S. Route 67 and U.S. Route 90. All of the route except for the section between Big Bend National Park and Farm to Market Road 170 is included in the Texas Historical Commission's Texas Mountain Trail. The road passes through or along several state and federal parks and other wildlife preservation areas. These include Big Bend National Park and Fort Davis National Historic Site of the National Park Service, Elephant Mountain Wildlife Management Area and Davis Mountains State Park operated by the Texas Parks and Wildlife Department, and the Davis Mountains Preserve of the Nature Conservancy of Texas. The road is in the Chihuahuan Desert and passes mostly through scrub land except in the higher elevations of the Davis Mountains where the road encounters forested sky islands. The road also provides access to the University of Texas at Austin's McDonald Observatory. History In 1927, the Texas Legislature authorized the Texas Highway Department, a precursor agency to TxDOT, to construct Davis Mountains State Park Highway after what was then the State Parks Board had failed to acquire parkland for a state park within the Davis Mountains. The road was to include portions of the present SH 118 and State Highway 166 now known as the Davis Mountains Scenic Loop. On August 17, 1926, SH 118 was designated from Marfa to Presidio. On March 19, 1929, the route was extended north to Fort Davis. On May 1, 1931, SH 118 was replaced by SH 17 and SH 118 was instead assigned on the old route of SH 3 from Alpine to Fort Davis which was completed. By 1932, the parks board finally acquired land for a park ending the need for a park highway. The road, which had then been built from Fort Davis to Fowlkes Ranch, was designated as SH 166. On December 22, 1936, SH 118 extended south to Terlingua. On September 26, 1939 when the state highway commission approved