Montana_meridian
Montana meridian
Geographic measurement from limestone hill in Montana
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.