Real estate maps show property information. This category of maps includes property ownership (cadastral maps), lot boundaries in new or subdivided developments (plat maps), detailed property evaluations (survey maps), and assessor information (parcel maps or assessor maps). For information on fire risk, including water lines, building materials, and type of structure, see our research guide on fire insurance maps. Real estate maps are excellent for finding out how an area was originally platted, who owned a particular plot of land at the time the map was made, and often will include building footprints. If you're tracking the development of a neighborhood or want to see building footprints over time, we recommend you explore both real estate maps as well as fire insurance maps, since both types of maps will show this and at different points in time. The overlap in content between the two types, even though varied and limited, makes them useful for looking at an individual property over time.
If you're specifically interested in researching building history in Denver, you will want to visit our Denver Building History Tutorial.
Special Collections and Archives' collection of real estate maps includes cadastral maps and some plat maps. These real estate maps were created at various scales by different cartographers, and frequently include various combinations of subdivision boundaries, lot configurations, and property ownership. The most detailed real estate maps, like Denver's Robinson's 1887 atlas and the Baist 1905 atlas, even show information more typically seen on fire insurance maps, such as building material.
Less detailed real estate maps like Marsh's atlases from the mid-20th century, show subdivision and addition boundaries and names, with larger properties outside of the developed areas showing property ownership. The library holds Marsh atlases for 1930, 1937, and 1960.
Many counties in Colorado have GIS Departments, and what they offer online will vary. Historic print plat maps are often held in County Surveyor's offices. The City and County of Denver hosts thousands of current and historic real property maps on its website, and you can find links to them in the Dig Deeper section on this page. The Denver Subdivision page provides digitized images of original plats establishing subdivisions, additions, and any adjustments made to them once established. The Denver Real Property page's Quarter Section maps show annotations, when and which land was vacated, and even building footprints.
Here's a quick guide to some of the City and County of Denver pages with plat maps
- Denver Subdivision maps: Original and resurveyed subdivisions and additions submitted by developers to the City. These provide lot configurations, street layout, with text indicating any special considerations and affirmations.
- Denver Quarter Section maps: So called because each small map encompasses one quarter of one section (160 acres) in the township and range system. These maps from the City Surveyor's Office date from the 1960s and 1970s, but with additional historic information on which ordinances affected the area over the history of the city. Information on quarter section maps include subdivision/addition names, streets, lot boundaries, street realignments, and overall are good for capturing the redevelopment of Denver during the middle of the 20th century.
Unless a property owner had a specific need and contracted with a professional surveyor, which can cost a substantial amount of money, it's likely that a detailed survey map was never created for that property. Survey maps for residential properties are not in the library's collection and are generally not held by city agencies. If they exist you can typically find any survey results, including maps, in the materials the owner receives when purchasing the property.
These maps are used to assess properties for tax purposes. Most often only the lot boundaries are shown, with some additional information on the size of the lot.
Robinson's Atlas of the City of Denver, Colorado, 1887
The Robinson Atlas will help you to date the construction of a building and give you a picture of neighborhood development. These maps also show the legal description of your building, which is necessary for locating many historic building records.
Baist Atlas 1905
Historical map of Denver, Colorado. Included is a listing of all Additions and Subdivisions until the year 1905.