Property owners in Colorado use several methods to research where their property lines run. Deeds, recorded plats, county parcel maps, BLM historical records, and physical survey monuments on the ground all provide information. But none of these methods establish a legally binding property line. Only a licensed Professional Land Surveyor can do that. This guide explains the available research methods, what each one tells you, and when you should hire a surveyor.
Start with Your Deed
Your property deed contains a legal description that defines your property. In Colorado, legal descriptions use three common formats:
- Lot-and-block: Used in platted subdivisions. The description references a lot number, block number, and subdivision name (for example, “Lot 12, Block 4, Greenfield Estates”). This refers to the recorded plat for the dimensions.
- Metes and bounds: Used for rural and mountain properties and older urban parcels. The description defines the boundary as a series of courses, each with a direction (bearing) and a distance. To physically locate a metes-and-bounds boundary, a surveyor must follow the courses from a defined starting point.
- Township-range-section: Part of the federal Public Land Survey System used across the western United States including Colorado. Rural parcels are often described as a fractional section of a township and range.
Your deed describes the property on paper but does not physically locate the lines on the ground. For that, you need additional research or a surveyor.
Check County Parcel Maps and GIS Portals
Most Colorado counties provide online GIS (Geographic Information System) portals showing parcel boundaries overlaid on aerial photography. These are useful for general orientation and can help you understand roughly where your property sits relative to neighboring parcels. Major Colorado counties have their own GIS portals: Denver, El Paso, Larimer, Weld, Jefferson, Boulder, and Arapahoe all provide public parcel search tools.
Important caveat: county GIS parcel maps are drawn from recorded deeds and plats and are not survey-grade accurate. The parcel lines on a GIS map can be off by 5 to 20 feet or more in some areas. They are a research starting point, not a substitute for a survey.
Find the Recorded Plat
If your property is in a platted subdivision, the recorded plat is the most accurate document for understanding your lot dimensions. Plats are filed with the county clerk and recorder and show lot widths, depths, setbacks from streets, and easements. Many Colorado counties have digitized their plat records and make them available online through the assessor or clerk and recorder.
The plat gives you the legal dimensions of your lot as recorded. However, over time, physical markers on the ground may drift from where the plat says they should be due to construction, erosion, or monument disturbance. The plat tells you what the survey said when it was recorded; it does not tell you where things stand today.
BLM General Land Office Records
Colorado is a public land state surveyed under the federal Public Land Survey System. The Bureau of Land Management maintains historical General Land Office (GLO) records at glorecords.blm.gov, including original township survey plats and field notes from the 19th and early 20th centuries. For rural and agricultural parcels, particularly in eastern Colorado, these original survey records are the foundation of the current property boundary system.
GLO records are useful background for understanding the history of a rural parcel but require professional interpretation. A surveyor uses these records as one piece of a larger research picture, alongside deeds, recorded plats, and field evidence.
Look for Physical Monuments on the Ground
When a licensed surveyor establishes or verifies property corners, they typically set a physical monument: an iron pin, a piece of rebar with a plastic cap stamped with the surveyor’s license number, or an aluminum survey disc. Look at the corners of your property, near fences, at sidewalk joints, or at curb cuts. Monuments are often set at grade or slightly below.
Important: Do not disturb or move anything that looks like a survey monument. Under C.R.S. 18-4-508, destroying or removing a survey monument is a criminal offense in Colorado. If you find a monument, note its location and share that with your surveyor.
Prior Survey Records
If a survey was performed on the property in the past, the plat may be on file at the county clerk and recorder or with the surveying firm that performed it. Ask the title company handling your transaction whether a prior survey is available; some title files include ILCs or plats from previous closings. A prior survey can give your new surveyor a starting point and reduce research time.
When Background Research Is Not Enough
All the methods above give you background information. None of them legally establish where your property lines run. If you need to:
- Build a fence, wall, or addition near a property line
- Resolve a dispute with a neighbor about the boundary
- Subdivide your property
- Establish corners for a sale or title insurance
- Determine whether a structure is encroaching on your lot
...you need to hire a licensed Professional Land Surveyor. Only a PLS can legally establish and certify property corners in Colorado, set monuments, and produce a plat that can be recorded at the county.
To find a licensed land surveyor in Colorado, browse our directory by county. Every surveyor listed is sourced from state licensing records maintained by the Colorado State Board of Licensure for Architects, Professional Engineers, and Professional Land Surveyors.