The Montana meridian extends north and south from the initial monument on the summit of a limestone hill, 800 feet (244 meters) high, longitude 110° 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. The initial point lies near Willow Creek, Montana.
- Nash, Stewart (01 February 2014) "Initial Point of Montana" Frederick, Maryland: The American Surveyor Magazine.
- 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). 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.