U.S. Route 66 in the state of Texas extended across the Texas Panhandle from its designation in 1926 to its decommissioning in 1985.

Glenrio, formerly Rock Island, is an unincorporated community in both Deaf Smith County, Texas, and Quay County, New Mexico, United States. Located on the former U.S. Route 66, the ghost town sits on the Texas–New Mexico state line. It includes the Glenrio Historic District, which was listed on the National Register of Historic Places in 2007.