Meades Ranch, Kansas
Meades Ranch is a location in Kansas, United States that was designated as the geodetic base point for the North American Datum of 1927 (NAD 27). It was chosen in 1901 because it was a triangulation station at the junction of the trancontinental triangulation arc of 1899 on the 39th parallel north and the triangulation arc along the 98th meridian west that was near the geographic center of the contiguous United States.    
Current (NAD83) location is Coordinates: or , 12 miles (19 km) north of Lucas, Kansas, 20 miles (32 km) south of Downs, Kansas, and 9 miles (14 km) southwest of Tipton, Kansas. A roadside marker describing Meades Ranch is 17 miles (27 km) north-northwest of Meades Ranch in a park just east of the junction of U.S. Route 24 and U.S. Route 281 in northeastern Osborne, Kansas. Meades Ranch is about 40 miles (64 km) south of the geographic center of the forty-eight contiguous U.S. states which is near Lebanon, Kansas.
The NAD27 system assumed Meades Ranch was 39 deg 13 min 26.686 sec north latitude, 98 deg 32 min 30.506 sec west longitude (NGS data). NAD27 was oriented by assuming the azimuth to Waldo was 255 deg 28 min 14.52 sec from north.
Meades Ranch was the reference point for almost all land survey measurements in the United States from 1927 until the establishment of the North American Datum of 1983 (NAD 83) and the World Geodetic System of 1984 (WGS84). NAD 27 used the Clarke ellipsoid of 1866. A reference ellipsoid is an attempt to closely describe mathematically the actual shape of the earth — the geoid. Calculations for map projections are performed using the parameters of the ellipsoid. The geoid, being irregular, is impossible to precisely model. For the purpose of the NAD 27, the geoidal height [i.e. geoid separation] at Meades Ranch was assumed to be zero so that the geoid (mean sea level) and the ellipsoid intersect at that location.
In popular culture
This geodetic center is featured in the 2006 documentary film Manhattan, Kansas by Tara Wray, which is about her reconciliation with her mentally unstable mother Evie Wray. Evie is shown searching for the Geodetic Center, the finding of which she says will bring about world peace.
- US Coast & Geodetic Survey, "Triangulation in Kansas", Special Publication No. 70 (1921)
- Bulletin of the National Research Council, Issues 77-80, p. 230
- Van Zandt, Boundaries of the United States and the several states, p. 265
- Walter H. Schoewe, "Kansas and the geodetic datum of North America", Transactions of the Kansas Academy of Science 51 (1948) 117–124, www.jstor.org
- Meades Ranch Reset, NGS Data Sheet
- Roadside marker in Osbourne, Kansas
- Frequently Asked Questions about the National Geodetic Survey
- Manhattan, Kansas at the Internet Movie Database
- Manhattan, Kansas review by the chutry experiment
- Documentary Educational resources