Near Billings, Montana is the disappointing Pictograph Cave State Park. Disappointing because unlike petroglyphs which are chipped in the varnish coating of rocks, pictographs are painted on. Paint fades and weathers. There are (were) dozens of pictographs in Pictograph Cave, but most are only visible in particular atmospheric conditions.
Pictograph Cave State Park
- American Computer and Robotics Museum
- Yellowstone County Museum