Montana Principal Meridian Initial Point, Montana

All of Montana was measured from this nameless hill in the southwestern part of the state, ten miles southwest of the headwaters of the Missouri River. It is one of 37 federal survey points of origin covering the USA (outside of the 13 original colonies), known as Initial Points, selected over a span of 150 years, to anchor newly acquired federal land to the legal and cartographic grid. The Surveyor General of the territory had imagined it being placed on a prominent landmark on the river known as Beaverhead Rock, but the surveyor in the field deemed it unsuitable and settled on this site instead. For some reason it was never given an official name, so Montana’s meridian is referred to descriptively as Principal Meridian, Montana. It was set in 1867, and is still marked by the three-inch brass cap placed there in 1922 by the U.S. Land Office. The site is surrounded by a private ranch.