The Centennial State
The land area of Colorado has roots in the Louisiana Purchase (1803), a Spanish land cession pursuant to the Adams-Onis Treaty (1819) the Annexation of Texas (1845) and a Mexican land cession pursuant to the Treaty of Guadalupe Hidalgo (1848). The present-day boundaries, in turn, are the result of a series of mid-nineteenth century legislative initiatives by the federal government.
As part of the Compromise of 1850, Texas, which entered the Union in 1845, traded land to the federal government in exchange for debt relief. Some of that land, along with other federal government holdings (from the 1848 Mexican cession) was organized into the New Mexico and Utah territories – their formation was also a part of the Compromise.


The New Mexico Principal Meridian (longitude 106° 53′ 12″ West) is the reference line for the San Luis Valley. The corresponding baseline for the New Mexico Principal Meridian runs across New Mexico at 34° 15′ 35″ North latitude. The Ute Principal Meridian (longitude 108° 31′ 59″ West) is the reference line for portions of Mesa and Delta counties on the Western Slope.
A legal description of property locates its township(s) relative to the appropriate baseline (north or south) and meridian (east or west). Property within a township is further defined by section – sections being 1 square mile divisions of a township.

Notes
1. In Colorado, counties are a basic unit of government, but land is divided into survey townships pursuant to centuries old federal legislation – the Land Ordinance of 1785.
