Meades Ranch Triangulation Station

Geodetic Center of the U.S.
U.S. National Register of Historic Places
Meades Ranch triangulation station, ca. 1940
Location of Meades Ranch in Kansas
Nearest city	Osborne, Kansas
Coordinates	39°13′27″N 98°32′32″W / 39.224087°N 98.542152°W / 39.224087; -98.542152
Built	1891 (1891)
NRHP reference No.	73000772[1]
Added to NRHP	October 9, 1973

The Meades Ranch Triangulation Station is a survey marker in Osborne County^[2] in the state of Kansas in the Midwestern United States. The marker was initially placed in 1891. From 1901, it was the reference location for establishing a system of horizontal measurement in the United States, known as geodetic datum. In 1913, the datum was adopted across all of North America, and the system revised and formalized as the North American Datum of 1927 (NAD27). A similar reference for vertical measurement was established in 1929 as the National Geodetic Vertical Datum of 1929. The NAD27 was later supplanted by the North American Datum of 1983 (NAD83), which was formally adopted by the United States in 1989 and Canada in 1990; the new system moved the reference point to a point in the Earth's core, and the Meades Ranch marker lost its special significance to the geodetic datum system.

In 1973, the site was listed in the National Register of Historic Places as the Geodetic Center of the United States.