Maps, Surveys & Boundaries
The principal meridians and base lines of the west are a product of the Northwest Ordinance of 1785. This measure provided for the orderly survey and sale of public lands. During the colonial period, New England had disposed of public lands by surveying them first and then selling them in orderly blocks. A system of "indiscriminate locations and subsequent survey" prevailed in the southern colonies. This permitted settlers to lay out the land they desired where they wished and then have it surveyed. The southern system led to conflicting titles as pioneers laid out irregularly shaped plots to claim the most fertile land and made it impossible for the government to dispose of the less desirable tracts. The survey of public lands was originally evolved in Ohio and was well developed by the time the West was settled.

The Ordinance of 1785 provided that the public lands of the United States be divided by lines intersecting true north and at right angles to form townships and ranges - both six miles square. The townships and ranges were to be marked with progressive numbers from the beginning, or "initial" point that was surveyed in a given area. Such townships and ranges were to be divided into thirty-six sections, each one mile square and containing 640 acres. The sections were to be numbered respectively, beginning with the number one in the northeast section and proceeding west and east alternately through the township with progressive numbers to thirty-six.

Note that townships are counted north-south of the initial point, while ranges are counted east-west.

In order to complete this type of surveying task, it was necessary to establish independent initial points to serve as bases for surveys. Principal meridians (north-south lines) and baselines (east-west lines) were then surveyed from these initial points. Guide meridians were initiated at baselines, and standard parallels were initiated at principal meridians to form townships.

transitIn Idaho the Initial Point is located about 8 miles south of Kuna. It is a volcanic hill  that was precisely located on April 19, 1867. Peter W. Bell used stellar observations to locate the point, by order of Lafayette Cartee, the first surveyor general of Idaho Territory. The Initial Point is marked with a small, round brass marker (about the size of a jam jar lid), and the hill is visible for miles around.

The principal meridian for Idaho is the exact north-south line as measured at Initial Point. It was called the Boise Meridian, and it runs the entire length of Idaho - from the Nevada border to the border with British Columbia.

The city of Meridian was named for the Boise Meridian as it lies exactly north on the surveyors line.

All surveys conducted in Idaho which divided the almost 54 million acres of unmapped lands are based from Initial Point.
Click here if you need to review some mapping terms & basics.