Fourth principal meridian explained

The fourth principal meridian, set in 1815,[1] is the principal meridian for land surveys in northwestern Illinois and west-central Illinois,[2] and its 1831[3] extension is the principal meridian for land surveys in Wisconsin and northeastern Minnesota. It is part of the Public Land Survey System that covers most of the United States.

The fourth principal meridian begins at a point on the west bank of the Illinois River in Schuyler County, Illinois. The fourth principal meridian's baseline, sometimes called the Beardstown baseline, runs west from this initial point. The meridian and this baseline governs surveys in Illinois that are west of both the Illinois River and the third principal meridian.

The Illinois Department of Transportation 2003 Survey Manual gives the point as 40.0139°N 90.4531°W and notes that the meridian is an extension of the line north from the mouth of the Illinois River near Grafton, Illinois.

Extended

The meridian was extended north in 1831, through Wisconsin and northeastern Minnesota. The extension uses the Illinois–Wisconsin border as its baseline, and is the basis of surveys in all of Wisconsin, as well as that part of Minnesota:

The initial point of the extended fourth principal meridian is located at 42.5075°N -90.4269°W.

See also

External links

Notes and References

  1. Book: Survey Manual. Illinois Department of Transportation, Bureau of Design and Environment. Springfield, Illinois. 2003-02-28. Chapter Five: Land Surveying. 5. 2008-10-30. 2011-05-25. https://web.archive.org/web/20110525044629/http://www.dot.state.il.us/desenv/survey/chap5.pdf. dead.
  2. Book: Raymond , William Galt . Plane Surveying for Use in the Classroom and Field . 2nd . 456 . via Google Books . 1914 . American Book Company . New York.
  3. 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.
  4. Minnesota Geospatial Information Office http://www.mngeo.state.mn.us/glo/Index.htm