List of principal and guide meridians and base lines of the United States explained

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.^[1] 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	data-sort-type="number"	Longitude !	Associated Baseline	data-sort-type="number"	Latitude !	Adopted	Area surveyed
	84°48′11″W		40°59′22″N	1819^[2]	Ohio (NW)
					Indiana (sliver of SE)
	86°27′21″W		38°28′14″N	1805	Illinois (far E)
					Indiana (almost all)
	89°08′54″W	Centralia	38°28′27″N	1805	Illinois (most)
	90°27′11″W	Beardstown	40°00′50″N	1815	Illinois (W of Illinois River and 3rd principal meridian)
	90°25′37″W	Illinois–Wisconsin border	42°30′27″N	1831	Minnesota (NE)
					Wisconsin (all)
	91°03′07″W		34°38′45″N	1815	Arkansas (all)
					Iowa (all)
					Minnesota (most)
					Missouri (all)
					North Dakota (all)
					South Dakota (E half)
	97°22′08″W		40°00′07″N	1855^[3]	Colorado (most)
					Kansas (all)
					Nebraska (all)
					South Dakota (some of S)
					Wyoming (most)
	104°03′16″W	Black Hills	43°59′44″N	1878^[4]	South Dakota (W)
	116°23′35″W		43°22′21″N	1867^[5]	Idaho (all)
	89°14′47″W		35°01′58″N	1833^[6]	Mississippi
	90°14′41″W	Choctaw	31°52′32″N	1821	Mississippi
	103°00′07″W		36°30′05″N	1881^[7]	Oklahoma (panhandle)
	145°18′37″W		61°49′04″N	1905^[8]	Alaska
	147°38′25.949″W		64°51′50.048″N	1910
	112°18′19″W		33°22′38″N	1865^[9]	Arizona (most)
	124°07′10″W		40°25′02″N	1853^[10]	California
	86°34′16″W		34°59′27″N	1807
					Mississippi
	97°14′49″W		34°29′32″N	1870	Oklahoma (most)
	158°45′31.014″W		65°26′16.374″N	1956
	92°24′55″W		31°00′31″N	1807	Louisiana
	84°21′53″W		42°25′28″N	1815
					Ohio
Montana	111°39′33″W		45°47′13″N	1867^[11]
	121°54′47″W		37°52′54″N	1851
	108°31′59″W		35°44′56″N	1869^[12]	Arizona (NE)
					New Mexico (NW, formerly)
	106°53′12″W		34°15′35″N	1855^[13]
					Colorado (SW)
	91°09′36″W		30°59′56″N	1819	Louisiana
	88°01′20″W	St. Stephens	30°59′51″N	1805
	111°53′27″W		40°46′11″N	1855^[14]	Utah (most)
	116°55′48″W		34°07′13″N	1852	California
					Arizona (some townships)
	149°21′26″W		60°07′37″N	1911
	84°16′38″W		30°26′03″N	1824
					Alabama
	109°56′06″W		40°25′59″N	1875	Utah (part of NE)
	152°00′04.551″W		69°23′29.654″N	1956	Alaska
	108°31′59″W		39°06′23″N	1880	Colorado
	91°09′36″W		30°59′56″N	1803	Mississippi
	122°44′34″W	Willamette	45°31′11″N	1851^[15]
	108°48′49″W		43°00′41″N	1875	Wyoming (part of W)

Guide Meridians

Meridian	data-sort-type="number"	Longitude !	Associated Baseline	data-sort-type="number"	Latitude !	Adopted	Area surveyed	Notes
Ashley guide meridian
Beaverhead guide meridian
Belt Mountain guide meridian
Big Hole guide meridian
Bitterroot guide meridian
Boulder guide meridian
Browning guide meridian
Buffalo Creek guide meridian
Carson River guide meridian
Castle Valley guide meridian
Colorado guide meridian
Columbia guide meridian
Colville guide meridian
Coulson guide meridian
Deer Lodge guide meridian
Deschutes meridian
Emery Valley guide meridian
Flathead guide meridian
Fort Belknap guide meridian
Fremont Valley guide meridian
Grand River guide meridian
Grande Ronde guide meridian
Green River guide meridian
Haystack Butte guide meridian
Helena guide meridian
Henry Mountain guide meridian
Horse Plains guide meridian
Humboldt River guide meridian
Jefferson guide meridian
Judith guide meridian
Kanab guide meridian
Kolob guide meridian
Little Porcupine guide meridian
Maginnis guide meridian
Musselshell guide meridian
New Mexico guide meridian
Panguitch guide meridian
Passamari guide meridian
Pine Valley guide meridian
Red Rock guide meridian
Reese River guide meridian
Ruby Valley guide meridian
Sevier Lake guide meridian
Shields River guide meridian
Smith River guide meridian
Snake Valley guide meridian
Square Butte guide meridian
Sweet Grass guide meridian
Teton guide meridian
Valley Creek guide meridian
Wah Wah guide meridian
Whatcom County guide meridian	122°30'					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
Yantic guide meridian
Yellowstone guide meridian

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

Notes and References

1. Book: Style Manual . 29th . 2000 . 18. Geologic Terms and Geographic Divisions . 346 . United States . . dead . https://web.archive.org/web/20080831023726/http://www.gpoaccess.gov/stylemanual/ . 2008-08-31 . GPO stock number 021-000-00178-3 (paper).
2. Web site: pob. blm.gov. 2012-01-03. https://web.archive.org/web/20130222061755/http://www.blm.gov/cadastral/meridians/pob.htm. 2013-02-22. dead.
3. Web site: 6pm. blm.gov. 2012-01-03. https://web.archive.org/web/20120814220341/http://www.blm.gov/cadastral/meridians/6prinmer.htm. 2012-08-14. dead.
4. Web site: 5thpmnorth. blm.gov. 2012-01-03. https://web.archive.org/web/20111213185442/http://www.blm.gov/cadastral/meridians/5pmnorth.htm. 2011-12-13. dead.
5. Book: National Mapping Program Technical Instructions: Standards for USGS and USDA Forest Service Single Edition Quadrangle Maps . Part 5: Public Land Survey System . Draft for Implementation . March 2003 . 5A-2 - 5A-4 . 2008-10-31 . dead . https://web.archive.org/web/20070103220000/http://rockyweb.cr.usgs.gov/nmpstds/acrodocs/draft/qmaps/5seqm503.pdf . 2007-01-03.
6. Web site: missalalou. blm.gov. 2012-01-03. https://web.archive.org/web/20130105115231/http://www.blm.gov/cadastral/meridians/missalalou.htm. 2013-01-05. dead.
7. Web site: oklahoma. blm.gov. 2012-01-03. https://web.archive.org/web/20130222075628/http://www.blm.gov/cadastral/meridians/oklahoma.htm. 2013-02-22. dead.
8. Web site: alaska. blm.gov. 2012-01-03. https://web.archive.org/web/20111220065252/http://www.blm.gov/cadastral/meridians/alaska.htm. 2011-12-20. dead.
9. Web site: arizona. blm.gov. 2012-01-03. https://web.archive.org/web/20111210172217/http://www.blm.gov/cadastral/meridians/arizona.htm. 2011-12-10. dead.
10. Web site: Calneva. blm.gov. 2012-01-03. https://web.archive.org/web/20110426033238/http://www.blm.gov/cadastral/meridians/Caleneva.htm. 2011-04-26. dead.
11. Web site: Monatana. blm.gov. 2012-01-03. https://web.archive.org/web/20150315072526/http://www.blm.gov/cadastral/meridians/Montana.htm. 2015-03-15. dead.
12. Hubbard, Bill, Jr. (2009) "Navajo meridian, 1869" American Boundaries: The nation, the states, the rectangular survey University of Chicago Press, Chicago, p. 338,
13. Web site: newmexico. blm.gov. 2012-01-03. https://web.archive.org/web/20111210172224/http://www.blm.gov/cadastral/meridians/newmexico.htm. 2011-12-10. dead.
14. Web site: utah. blm.gov. 2012-01-03. https://web.archive.org/web/20100518120142/http://www.blm.gov/cadastral/meridians/utah.htm. 2010-05-18. dead.
15. Web site: orewash. blm.gov.