Writing Rock State Historical Site, located twelve miles northeast of
Grenora, North Dakota in
Divide County near the
Montana border, is the site of two large granite boulders, carved with
petroglyphs featuring
thunderbirds, mythological creatures that are of importance in the culture of
Plains Indian tribes. The age of the carvings has not been determined, but they could date from 1000 to about 1700, according to the North Dakota Historical Society.
It is located at