Geographic center of the
contiguous United States

Lebanon, Kansas
S.W. and J.S. Aber


Introduction

The U.S. Coast and Geodetic Survey identified the geographic center of the United States in 1918 approximately one mile north and one mile west of Lebanon, Kansas. Determining this location was done by balancing a cut-out shape of the United States on a point. The method was considered accurate to within 20 miles. When Alaska and Hawaii were added as states in 1959, this location became the geographic center of the contiguous (48) states, and the geographic center for the (whole) United States shifted north and west to near Belle Fourche, South Dakota.

Historical marker on US 36/281 highways, one mile south of Lebanon, Kansas. Left – SWA points to the center. Right – detail of the map showing the outline of Kansas, Lebanon (red star), and highway mileages to selected cities.

The geographic center of the contiguous U.S. is defined as 39°50' N latitude, 98°35' W longitude (+39.833333°, -98.583333° decimal degrees). This position is located on private land, so a proxy marker was erected in 1940 in a small public park about half a mile from the official location. This park is accessed via state highway 191, one mile west from US 281. The monument is constructed of sandstone and conglomerate from the Ogallala Formation, which crops out a few miles to the west.

Plaque on the monument for the geographic center of the contiguous U.S. Located in the public park at K-191 and Smith County AA Road.

We had the opportunity to visit Lebanon in early June 2021 in connection with geological field work in the vicinity. We flew our large rokkaku in the early afternoon on a southeasterly breeze at 10-15 mph under sunny sky. We set up beside AA Road at the edge of a recently mowed hay field about one-third of a mile south of the park. It proved to be an ideal location to overview the geographic center of the contiguous United States.

KAP at the geographic center of the contiguous U.S.
Left: official center of the contiguous United States (*) is located in a field on private cropland. The public park (<) is a small triangle at the junction of K-191 highway and Smith County AA Road. View toward the north. Right: closer view of the public park (<) and access roads.
Left: closest view of the public park (<). The long building (*) is an abandoned motel. Right: looking eastward with Lebanon visible in the right distance. Summer crops are just beginning to emerge in the tilled fields.
Kite flyers operating beside AA Road. The bold stripes represent newly mown hay that is drying in the field before baling.

References and related sites



48-star flag (1912-1959)

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All text and images © by the authors (2021).