Fort McKavett State Historical Site
The 150-year-old Fort McKavett in southwest Texas is considered one of the best preserved military posts from the Texas Indian Wars (1850-1875). Lack of light makes the place a popular place for astronomy events. Note, however, that special permission is required to enter after hours outside of scheduled events.
An EarthSky community member says: “The fort is 150 miles (240 km) northwest of the city lights of the nearest city San Antonio, and 15 miles (24 km) north of Interstate 10… located just west of the 100th meridian. Knowledgeable NASA and other guests participate in annual spring stargazing event at the state park site.”