During the latter half of the 1800's, surveyors laid out the Public Land Survey System in Colorado. Measurements were made as accurately as possible with the equipment available at the time, but the primary purpose of these surveys was to monument the land into one-mile square parcels called sections. 
The sections were then dispersed to the public in exchange for money or public service, including military service and promises to improve the land (homesteading). These sections, as monumented, are still referred to in legal descriptions, subdivision plats, and other documents.
Today, surveys are used for a variety of reasons (see Common questions and answers). These include getting a home mortgage, building new improvements, and making sure that your real estate investment is protected. The expense of having a property surveyed will probably be less than the cost of moving a new building, relocating improvements, or defending against a lawsuit over a land boundary.
