Talk:109th meridian west

From Wikipedia, the free encyclopedia
Jump to: navigation, search


On 1850-09-28, the United States officially adopted the Prime Meridian of Greenwich for all nautical and international use, but also adopted the Washington Meridian (based upon the old United States Naval Observatory) for astronomical and official domestic use. Although the Greenwich Meridian was widely employed, the United States retained the Washington Meridian for official domestic use until the Greenwich Meridian was officially adopted for all uses on 1912-08-22. The borders of most western territories were defined during this period. Since the old United States Naval Observatory is 2.76 miles (4.44 kilometers) west of the meridian 77° west of Greenwich, most western states have borders 2.0 to 3.5 miles (3.2 to 5.6 kilometers) west of their Greenwich-based meridians.

The Enabling Act of the Territory of Colorado[1] dated February 28, 1861, states that the extent of the territory (and the future state) shall be defined by the metes and bounds "commencing on the thirty-seventh parallel of north latitude, where the twenty-fifth meridian of longitude west from Washington crosses the same; thence north on said meridian to the forty-first parallel of north latitude; thence along and parallel west to the thirty-second meridian of longitude west from Washington; thence south on said meridian to the northern line of New Mexico; thence along the thirty-seventh parallel of north latitude to the place of beginning."

The actual state boundaries are defined by government surveys which deviate from the theoretical borders by small distances. The most recent National Geodetic Survey measurement of the Four Corners Monument[2] places the monument at 36°59'56.31532"N 109°02'42.62019"W, about 114 meters (375 feet) south of the 37th parallel north and about 4.0 kilometers (2.5 miles) west of the 109th meridian west.

--Buaidh 05:31, 4 January 2007 (UTC)


  1. ^ "An Act to provide a temporary Government for the Territory of Colorado" (PDF). Thirty-sixth United States Congress. February 28 1861. Retrieved January 3, 2007.  Check date values in: |date= (help)
  2. ^ "Four Corners PID AD9256" (text file). NGS Survey Monument Data Sheet. United States National Geodetic Survey. May 7, 2003. Retrieved January 3 2007.  Check date values in: |access-date= (help)