Principal Meridians

Meridian Longitude Associated Baseline Latitude Adopted Area surveyed
First principal 84°48′11″W 40°59′22″N 1819[2] Ohio (NW)
Indiana (sliver of SE)
Second principal 86°27′21″W 38°28′14″N 1805[2] Illinois (far E)
Indiana (almost all)
Third principal 89°08′54″W Centralia 38°28′27″N 1805[2] Illinois (most)
Fourth principal 90°27′11″W Beardstown 40°00′50″N 1815[2] Illinois (W of Illinois River and 3rd principal meridian)
Fourth principal (extended) 90°25′37″W Illinois–Wisconsin border 42°30′27″N 1831[2] Minnesota (NE)
Wisconsin (all)
Fifth principal 91°03′07″W 34°38′45″N 1815[3] 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[4] 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[3] South Dakota (W)
Boise[1] 116°23′35″W 43°22′21″N 1867[5] Idaho (all)
Chickasaw 89°14′47″W 35°01′58″N 1833[6] Mississippi
Choctaw 90°14′41″W Choctaw 31°52′32″N 1821[6] Mississippi
Cimarron 103°00′07″W 36°30′05″N 1881[7] Oklahoma (panhandle)
Copper River 145°18′37″W 61°49′04″N 1905[8] Alaska
Fairbanks 147°38′25.949″W 64°51′50.048″N 1910[8] Alaska
Gila and Salt River 112°18′19″W 33°22′38″N 1865[9] Arizona (most)
Humboldt 124°07′10″W 40°25′02″N 1853[10] California
Huntsville 86°34′16″W 34°59′27″N 1807[6] Alabama
Mississippi
Indian 97°14′49″W 34°29′32″N 1870 Oklahoma (most)[7]
Kateel River 158°45′31.014″W 65°26′16.374″N 1956 Alaska[8]
Louisiana 92°24′55″W 31°00′31″N 1807[6] Louisiana
Michigan 84°21′53″W 42°25′28″N 1815[2] Michigan
Ohio
Montana 111°39′33″W 45°47′13″N 1867[11] Montana
Mount Diablo 121°54′47″W 37°52′54″N 1851[10] California
Nevada
Navajo 108°31′59″W Navajo 35°44′56″N 1869[1][9][12] Arizona (NE)
New Mexico (NW, formerly)
New Mexico principal 106°53′12″W 34°15′35″N 1855[13] New Mexico
Colorado (SW)
St. Helena 91°09′36″W 30°59′56″N 1819[6] Louisiana
St. Stephens 88°01′20″W St. Stephens 30°59′51″N 1805[6] Alabama
Mississippi
Salt Lake 111°53′27″W 40°46′11″N 1855[14] Utah (most)
San Bernardino[10] 116°55′48″W 34°07′13″N 1852[1][5] California
Arizona (some townships)
Seward 149°21′26″W 60°07′37″N 1911[8] Alaska
Tallahassee 84°16′38″W 30°26′03″N 1824[6] Florida
Alabama
Uintah 109°56′06″W 40°25′59″N 1875[14] Utah (part of NE)
Umiat 152°00′04.551″W 69°23′29.654″N 1956[8] Alaska
Ute 108°31′59″W 39°06′23″N 1880[4] Colorado
Washington (Mississippi) 91°09′36″W 30°59′56″N 1803[6] Mississippi
Willamette 122°44′34″W Willamette 45°31′11″N 1851[15] Oregon
Washington
Wind River 108°48′49″W 43°00′41″N 1875[4] Wyoming (part of W)