SH 115 begins at an intersection with Interstate 20 and Farm to Market Road 1927 in Pyote. The route travels north along the eastern edge of town and through Far West Texas oil fields before reaching Wink. The route then turns northeast, next reaching Kermit. The route travels through downtown Kermit, passing the Winkler County Courthouse. The route continues to the northeast, crossing oil fields of Winkler and Andrews Counties, before reaching Andrews. The route travels through Andrews, intersecting U.S. Route 385. The route continues northeast, crossing through the intersection of Andrews, Gaines, Martin, and Dawson Counties before reaching its terminus at SH 349 at the unincorporated community of Patricia, Texas.
SH 115 was originally proposed by 1928 as a route from north of Amarillo to Stratford into Oklahoma. By 1933, this route became an extension of SH 9. SH 115 was redesignated as a short route between Pyote and Wink. The route was extended to its current length in 1990, replacing Farm to Market Road 703.
FM 703 was originally designated in 1946 from Kermit to the Andrews County Line. In 1948, FM 703 extended northeast to the Dawson/Gaines/Martin County Line. Later that year, FM 703 extended to Patricia, completing its routing before 1990. In 1990, FM 703 was transferred to SH 115.