Gila and Salt River Meridian Initial Point, Arizona

All of Arizona (except a portion of the Navajo Reservation) was surveyed from this hilltop anchor point west of Phoenix. 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 the course of 150 years, to anchor newly acquired federal land to the legal and cartographic grid. The Initial Point for the survey of Arizona lies atop a 150-foot tall hill called Monument Hill. This site was selected as it has a good view and is visible from around the area, and because it lies next to a major regional geographic feature, the confluence of the Gila River and the larger Salt River. The site was originally surveyed and marked with an eight-foot tall rock monument in 1851, as part of the U.S./Mexico boundary survey. So when the field work for the territorial survey was started in 1865, this made a solid, already-established point to base it from. An early version of the  current monument was made in 1984, during the first annual “National Surveyors Week,” by several entities working together, including the BLM, the Gila River Indian Community, and the local chapter of the Arizona Professional Land Surveyors. The monument has been vandalized and repaired a few times since then, including a major restoration in 2006, which rebuilt the concrete cross with the tile inlay.