The Montana meridian extends north and south from the initial monument on the summit of a limestone hill, 800 feet (240 meters) high, longitude 111° 39′ 33″ west from Greenwich, and, with the base line on the parallel of 45° 47′ 13″ north latitude, governs the surveys in the state of Montana.^[1] The initial point lies near Willow Creek, Montana.

• List of principal and guide meridians and base lines of the United States

• Raymond, William Galt (1914). Plane Surveying for Use in the Classroom and Field (via Google Books). New York: American Book Company.

• "Montana". U.S. Bureau of Land Management (BLM). Archived from the original on 2015-03-15. Retrieved 2012-09-25.
• "Montana Principal Meridian". The Center for Land Use Interpretation. Retrieved 2012-09-25.
• "Principal Meridian of Montana, Willow Creek, MT". Principal Meridian Project. Retrieved 2012-09-25.

45°47′12.82″N 111°39′35.57″W / 45.7868944°N 111.6598806°W / 45.7868944; -111.6598806