The following are the principal and guide meridians and base lines of the United States, with the year established and a brief summary of what areas' land surveys are based on each.

List of meridians Primarily from the United States Government Printing Office Style Manual. GPO stock number 021-000-00178-3 (paper). State names usually signify only parts of each listed state, unless otherwise indicated.

Based on the BLM manual's 1973 publication date, and the reference to Clarke's Spheroid of 1866 in section 2-82, coordinates appear to be in the NAD27 datum.

Principal Meridians

Meridian Longitude Associated Baseline Latitude Adopted Area surveyed First principal 84°48′11″W 40°59′22″N 1819 Ohio (NW) Indiana (sliver of SE) Second principal 86°27′21″W 38°28′14″N 1805 Illinois (far E) Indiana (almost all) Third principal 89°08′54″W Centralia 38°28′27″N 1805 Illinois (most) Fourth principal 90°27′11″W Beardstown 40°00′50″N 1815 Illinois (W of Illinois River and 3rd principal meridian) Fourth principal (extended) 90°25′37″W Illinois–Wisconsin border 42°30′27″N 1831 Minnesota (NE) Wisconsin (all) Fifth principal 91°03′07″W 34°38′45″N 1815 Arkansas (all) Iowa (all) Minnesota (most) Missouri (all) North Dakota (all) South Dakota (E half) Sixth principal 97°22′08″W 40°00′07″N 1855 Colorado (most) Kansas (all) Nebraska (all) South Dakota (some of S) Wyoming (most) Black Hills 104°03′16″W Black Hills 43°59′44″N 1878 South Dakota (W) Boise 116°23′35″W 43°22′21″N 1867 Idaho (all) Chickasaw 89°14′47″W 35°01′58″N 1833 Mississippi Choctaw 90°14′41″W Choctaw 31°52′32″N 1821 Mississippi Cimarron 103°00′07″W 36°30′05″N 1881 Oklahoma (panhandle) Copper River 145°18′37″W 61°49′04″N 1905 Alaska Fairbanks 147°38′25.949″W 64°51′50.048″N 1910 Alaska Gila and Salt River 112°18′19″W 33°22′38″N 1865 Arizona (most) Humboldt 124°07′10″W 40°25′02″N 1853 California Huntsville 86°34′16″W 34°59′27″N 1807 Alabama Mississippi Indian 97°14′49″W 34°29′32″N 1870 Oklahoma (most) Kateel River 158°45′31.014″W 65°26′16.374″N 1956 Alaska Louisiana 92°24′55″W 31°00′31″N 1807 Louisiana Michigan 84°21′53″W 42°25′28″N 1815 Michigan Ohio Montana 111°39′33″W 45°47′13″N 1867 Montana Mount Diablo 121°54′47″W 37°52′54″N 1851 California Nevada Navajo 108°31′59″W Navajo 35°44′56″N 1869Hubbard, Bill, Jr. (2009) "Navajo meridian, 1869" American Boundaries: The nation, the states, the rectangular survey University of Chicago Press, Chicago, p. 338, Arizona (NE) New Mexico (NW, formerly) New Mexico principal 106°53′12″W 34°15′35″N 1855 New Mexico Colorado (SW) St. Helena 91°09′36″W 30°59′56″N 1819 Louisiana St. Stephens 88°01′20″W St. Stephens 30°59′51″N 1805 Alabama Mississippi Salt Lake 111°53′27″W 40°46′11″N 1855 Utah (most) San Bernardino 116°55′48″W 34°07′13″N 1852 California Arizona (some townships) Seward 149°21′26″W 60°07′37″N 1911 Alaska Tallahassee 84°16′38″W 30°26′03″N 1824 Florida Alabama Uintah 109°56′06″W 40°25′59″N 1875 Utah (part of NE) Umiat 152°00′04.551″W 69°23′29.654″N 1956 Alaska Ute 108°31′59″W 39°06′23″N 1880 Colorado Washington (Mississippi) 91°09′36″W 30°59′56″N 1803 Mississippi Willamette 122°44′34″W Willamette 45°31′11″N 1851 Oregon Washington Wind River 108°48′49″W 43°00′41″N 1875 Wyoming (part of W)

Guide Meridians

Meridian Longitude Associated Baseline Latitude Adopted Area surveyed Notes Ashley guide meridian Utah Beaverhead guide meridian Montana Belt Mountain guide meridian Montana Big Hole guide meridian Montana Bitterroot guide meridian Montana Boulder guide meridian Montana Browning guide meridian Montana Buffalo Creek guide meridian Montana Carson River guide meridian Nevada Castle Valley guide meridian Utah Colorado guide meridian Utah Columbia guide meridian Washington Colville guide meridian Washington Coulson guide meridian Montana Deer Lodge guide meridian Montana Deschutes meridian Oregon Emery Valley guide meridian Utah Flathead guide meridian Montana Fort Belknap guide meridian Montana Fremont Valley guide meridian Utah Grand River guide meridian Utah Grande Ronde guide meridian Oregon Green River guide meridian Utah Haystack Butte guide meridian Montana Helena guide meridian Montana Henry Mountain guide meridian Utah Horse Plains guide meridian Montana Humboldt River guide meridian Nevada Jefferson guide meridian Montana Judith guide meridian Montana Kanab guide meridian Utah Kolob guide meridian Utah Little Porcupine guide meridian Montana Maginnis guide meridian Montana Musselshell guide meridian Montana New Mexico guide meridian New Mexico and Colorado Panguitch guide meridian Utah Passamari guide meridian Montana Pine Valley guide meridian Utah Red Rock guide meridian Montana Reese River guide meridian Nevada Ruby Valley guide meridian Nevada Sevier Lake guide meridian Utah Shields River guide meridian Montana Smith River guide meridian Montana Snake Valley guide meridian Utah Square Butte guide meridian Montana Sweet Grass guide meridian Montana Teton guide meridian Montana Valley Creek guide meridian Montana Wah Wah guide meridian Utah Whatcom County guide meridian 122°30' Willamette Meridian Whatcom County, Washington 12 miles east of Willamette Meridian, much of which is in Salish Sea at this latitude. Followed by Guide Road / Old Guide Road / Washington State Route 539 in Whatcom County, Meridian Street in Bellingham, Washington. Willow Springs guide meridian Utah Yantic guide meridian Montana Yellowstone guide meridian Montana

Ohio Lands Some parts of the Ohio Lands (now Ohio) were laid out in survey townships, but based on other points not listed above: Base Line of the United States Military Survey (1797) Great Miami River baseline (1798) Ohio River (1785) — also part of Indiana Muskingum River baseline (1800) Scioto River baseline (1799) Twelve Mile Square Reserve (1805)

See also Public Land Survey System — the basis of most meridians in the United States

References