New Mexico Principal Meridian, New Mexico

The survey of the Territory of New Mexico began in 1855, with the establishment of this Initial Point atop a butte in the central part of the state, 235 feet above the Rio Grande, and marked by a pile of rocks. 100 years later, in 1956, the scattered stones from the original pile were cross referenced by peripheral monuments (it is standard practice to mark and record fixed points, such as trees and rocks, around important survey points, in case the main marker is lost), and a modern brass BLM survey medallion was affixed into a concrete base in the usual style of the time. No other changes to the site have been made since. 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. All of New Mexico and some of Colorado were surveyed from this Initial Point.