GEOLOGY OF THE KILDEER MOUNTAINS 261 
northward course along Tobacco Garden Creek to its present east- 
ward course 6 miles north of the Killdeer Mountains. 
Stream piracy.—Formerly the divide between the Missouri and 
the Little Missouri rivers followed the long axis of the Killdeer 
Fic. 4.—A representation of the change in a divide due to rejuvenation. The 
line of dashes denotes the position of the old divide between the Missouri and Little 
Missouri rivers. The dots and dashes indicate the present divide between two 
tributaries of the Little Missouri River. Note capture of the head of Charlie Bob 
Creek by Jim Creek, and the gorge cut in the old valley floor. 
Mountains from north to south; now it passes along the south 
stretch of the South Mountain from west to east. The maps (Figs. 
2 and 5) show what a considerable amount of stream capture 
attended the change. That part of the Little Missouri River 
