Enchanted Rock State Natural Area spans the border between Gillespie County and Llano County, south of the Llano River and some 24 km north of Fredericksburg, Texas. Popular activities at the park include star gazing, caving, hiking, primitive backpack camping, rock climbing and picnicking. It is a designated Dark Sky preserve as of 2014. Enchanted Rock has hosted star parties for park visitors since 2011.
Link to Park Site

Mailing address:
16710 Ranch Rd. 965
Fredericksburg, TX 78624

South Llano River State Park is the third Texas state park to be designated as an International Dark Sky Park, joining Copper Breaks State Park located in the Texas Panhandle and Enchanted Rock State Park in the Hill Country. Located five miles from the nearest town, the South Llano River State Park ranks as a “3” on the Bortle Scale which ranks skies from 1 to 9, with one being the darkest skies and nine being the least dark.
Link to Park Site

Mailing address:
1927 Park Road 73
Junction, TX 76849

Copper Breaks State Park, located in northern Texas some 21km south of the town of Quanah, contains two small lakes and 16 km of trails. “Breaks” refers to the fractures and faults that define the limited waterways of the park. The land comprising the park was historically held by the Comanche and Kiowa Native American tribes and were purchased from a private landowner in 1970. Since 1996 the park has capitalized on its superb celestial assets by hosting Star Walks and other astronomy programs.
Link to Park Site

Mailing address:
777 State Hwy Park Rd 62,
Quanah, TX 79252