(Montana)
Painted Rocks State Park is a public recreation area located at the southern end Painted Rocks Reservoir, 24 miles (39 km) south of Darby, Montana. The state park received its name from the green, yellow and orange lichens which cover the grey and black rock walls of the granite and rhyolite cliffs. The park has Bortle scale class 1 skies which makes the state park a great place for astronomy as it is far away from light pollution. (Ref: https://en.wikipedia.org/wiki/Painted_Rocks_State_Park)