List of geographic centers of the United States
From Wikipedia, the free encyclopedia
This is a list of geographic centers of each U.S. state and inhabited territory. The geographic center of the United States is northeast of Belle Fourche in Butte County, South Dakota (44°58′N 103°46′W),[1] while that of the contiguous 48 states is near Lebanon in Smith County, Kansas (39°50′N 98°35′W).[1] The geographic center of North America lies near Rugby, North Dakota (48°10′N 100°10′W), though this designation has no official status.[1] In 2017, a new calculation of the geographic center of North America placed it near the town of Center, North Dakota.[2]
Historic list of geographic centers
The list given below has been only slightly modified since it was first produced by the U.S. Geological Survey (USGS) in the early 1920s.[3] At that time, the center for a state was found by suspending a cardboard cutout of the state by a string, and then drawing a vertical line from the suspension point. After rotating the cutout 90 degrees and drawing another vertical line from the new suspension point, the intersection of the two vertical lines was used as the geographic center.[4] The result is dependent upon the type of projection used.
Modern list of geographic centers
Although there have been different definitions offered for the geographic center, an intuitive one, and one used by the USGS, is "the center of gravity of the surface, or that point on which the surface of the area would balance if it were a plane of uniform thickness."[7] An updated list of geographic centers using this definition (which is equivalent to the state's centroid) is given below. It was derived by minimizing the sum of squared great circle distances from all points of land in a state (including islands, but not coastal waters, following the earlier practice of the USGS). It represents a slight improvement over the list originally published.[8]
The geographic center of the contiguous United States, determined in this way, is at 39°50.13′N 99°5.45′W; this is 5.4 miles (8.7 km) from Agra, Kansas, 5.7 miles (9.2 km) from Kensington, Kansas, and 26.9 great circle miles (43.3 km) west of the longstanding designated site near Lebanon, Kansas.
Geographic centers of the U.S. territories
Very little information exists about the geographic centers of the U.S. territories. In a geological survey of all geographic centers in the U.S., the U.S. Department of the Interior did not measure the geographic centers of the U.S. territories.[9] Similarly, the USGS does not include the territories in its list of geographic centers.[1] In terms of each territory’s land area, only one territory, Puerto Rico, has a confirmed geographic center.[10] There are also official geographic centers of territorial exclusive economic zones, though those geographic centers are based on a territory's territorial waters (not land area).
| Territory | County- equivalent |
Location | Coordinates |
|---|---|---|---|
 American Samoa | North of Manu’a District (EEZ) Eastern District (Tutuila center) | The geographic center of American Samoa’s exclusive economic zone (EEZ) is located in the Pacific Ocean, about 35.08 miles (56.45 km) northeast of the island of Ta‘ū.[11] The geographic center of Tutuila (the main island) is about 1.03 miles (1.65 km) southwest of Fagatogo.[12] | 13.8517°S 169.0576°W (EEZ center) 14.2901°S 170.7028°W (Tutuila center) |
 Guam | Guam[note 2] | The geographic center of Guam’s exclusive economic zone is in the Pacific Ocean, about 73.65 miles (118.53 km) west-southwest of Cocos Island and 76.08 miles (122.45 km) west-southwest of the main island of Guam.[13] The exact geographic center of the main island of Guam is unknown[14] — it is probably somewhere within the village of Chalan Pago-Ordot, because that is the default center starting point of Guam on Google Maps.[15] | 12.9770°N 143.5814°E (Center of EEZ) 13.4440°N 144.7671°E (Chalan Pago-Ordot) |
 Northern Mariana Islands | Northern Islands Municipality | The geographic center of the Northern Mariana Islands’ exclusive economic zone is in the Pacific Ocean, about 18.33 miles (29.50 km) northeast of the island of Pagan.[16] | 18.3183°N 146.0284°E (EEZ center) |
 Puerto Rico | Orocovis Municipality | The geographic center of Puerto Rico is in the Orocovis Municipality, about 2.58 miles (4.15 km) west of the main town of Orocovis.[10] | 18.2223°N 66.4303°W |
 U.S. Virgin Islands | Between Saint Thomas and Saint Croix | The exact geographic center of the U.S. Virgin Islands is unknown — the default center starting point for the U.S. Virgin Islands on Google Maps is located in the Caribbean Sea,[15] 18.21 miles (29.30 km) south-southeast of Saint Thomas and 18.31 miles (29.47 km) north of Saint Croix — note that this point is the approximate center of the 3 main islands, not the center of the exclusive economic zone | 18.34°N 64.90°W |
 U.S. Minor Outlying Islands | [note 3] | There is no information about the geographic centers of the islands in the U.S. Minor Outlying Islands (or the U.S. Minor Outlying Islands as a whole). |
See also
- Geographic center of the contiguous United States
- Geographic center of the United States
- List of extreme points of the United States
- List of extreme points of U.S. states and territories
- List of U.S. states and territories by elevation
- Mean center of the United States population
- Median center of United States population
Notes
- The U.S. Census Bureau treats the District of Columbia as a state-equivalent and a county-equivalent for statistical purposes.
- All of Guam is counted as one county-equivalent by the U.S. Census Bureau.
- Each of the 9 island groups in the U.S. Minor Outlying Islands is counted as a county-equivalent by the U.S. Census Bureau.