Much of the range formation was caused by wind, river and lake erosion.

The Killdeer Mountains cover a surface of 26 square kilometers (10 sq mi).

[2][3] The range's name comes from the Native Americans, who used the area as a hunting ground for deer.

[4] The range was the scene of the Battle of Killdeer Mountain in 1864.

[5] However, no geological evidence has proven a confirmed volcano in the area.