Colorado Road Maps

While the definition of 'road map' varies over time, this guide is all about maps intended to help people use roads, paved or unpaved, to get from one place to another within Colorado. From primitive trails on historic maps to interstate highways and GIS (geographic information system) data. Many of the road maps described below show all transportation routes, including railroads, though railroads are not the focus of this research guide.

Trail Maps

Before recreational hiking, trails and waterways were the primary means of getting from A to B, and were utilized by travelers and merchants for centuries. Colorado does not have the abundance of navigable waterways that states farther east can claim, but it does contain plenty of trail networks across the plains and over the mountains. Early 19th century surveys and exploration maps almost always include their own routes, and frequently include other trails too.

It is rare for any information to be given on these maps regarding the specific condition or width of the trails shown. Early topographic maps by American surveyors, and later the U.S. Geological Survey, continued to show trails and over time, began to separate them from wagon roads. 

Perhaps the best way to see most of them in one place is Glenn Scott's Historic Trail Map series covering much of eastern Colorado, including the Front Range. These maps overlay historic trail routes on top of a modern map to provide context. This series involved a late-1970s collaboration between the U.S. Geological Survey and Denver Public Library's Western History Department (now Special Collections and Archives). Most maps and related booklets in this set are available for download.

Wagon Roads

American government surveyors from the 1840s through the 1870s crisscrossed the western territories, mapping trails they discovered, wagon roads used, and sometimes provided information on each. Explorers like John C. Fremont (nicknamed "The Pathfinder"), Lt. George Wheeler, and Ferdinand V. Hayden created maps that, while small-scale in nature and for different reasons, took pains to highlight the best transportation routes. The terms trails and 'wagon roads' were fuzzy during this time. For example, the Santa Fe Trail -- which was really a network of intertwining routes -- was heavily used by wagon trains.

While not labeled as such, when today's maps list a road as "unimproved" it is largely the same as a wagon road: a rough dirt road usually, though not always, wide enough for two vehicles.

Postal Route Maps (1877-present)

Not commonly thought of in this category is an unusual series of government publications known as "Post Route" maps. Published for Colorado irregularly since 1877, the library holds scattered print editions from 1878 to 1953, some of which give mail delivery frequency and discontinued post office -- something that happened often with boom and bust mining towns. The digitized 1878 edition is available for free download. Today's postal maps are in the form of GIS data, and are also available for free downloading from the U.S. Postal Service.

Old or new, these are good for finding places where roads existed, though are lacking in information on what types of roads were present.

Early Automobile Maps (1910-1930)

Initially a luxury product, automobiles quickly developed from a rarity into the mainstream within a roughly 20-year span from the early 20th century into the 1920s. With the passage of a 1909 highway bill creating the first State Highway Commission. Road maps featuring state-approved routes began turning up by 1912, though the Clason Map Company issued a road map designed for automobiles as early as 1908. These early highway maps informed drivers on how well maintained they were (paved, gravel, 'oiled' (to keep the dust down and resist water erosion), dirt, or unimproved). 

Early "routes" were just that. They utilized existing non-highway roads, which necessitated a series of sharp turns from road to road. Finding the correct route to your destination became challenging, resulting in drivers and merchants along major routes banding together to form associations for the purpose of both tying specially marked bands around telephone poles adjacent to the roads, and to advocate for road condition improvements to encourage travel. Road maps in the early 1900s soon began to include illustrated guides showing what patterns to follow for which route. 

The larger road associations published tourist brochures well into the 20th century, with maps and illustrations promoting the route, like this 1960 U.S. 287 brochure.

State Highway Maps (1912-present)

Beginning around 1912 the State Highway Department began issuing its own state road and highway maps -- a practice that continues to this day. The library collects all available editions, though there are gaps in coverage. To target winter sports enthusiasts, Colorado issued a special winter edition of the map in the late 1960s and 1970s highlighting cold-weather activities and destinations, special travel advice for slippery conditions, and closures of mountain passes.

These folded maps typically featured a colorful mountain scene on the main outer panel, with a visually appealing shaded-relief road map inside. 

Statewide County General Highway Maps (1936-1980)

Less colorful but much more detailed began as a Works Progress Administration (WPA) project in the mid-1930s, partnering the Federal Highway Administration with state highway departments across the country. This fruitful collaboration produced county-by-county maps showing a large variety of roads, abandoned and active buildings, cemeteries, and other features that captured the development of Colorado every few years during the mid-20th century -- a period of rapid change in the state.

The WPA closed its doors in the early 1940s, but the county map project itself lasted from its origins in 1936 until around 1980. Updates were irregular, but most counties received around ten updates during that time. To decide if this set might help you in your research, check out the full listing of the library's holdings in this series.

Current Road and Highway Information

To get current information several options are available, all of which are free of charge:

• Printed state highway maps continue to be issued and are available by ordering directly from the Colorado Department of Transportation, and can be found at most tourist information centers
• The U.S. Census maintains its long-running TIGER GIS data files, which include detailed street and road network information for each state
• Colorado's Department of Transportation provides public GIS data for Colorado roads and facilities

Additional Sources

The story of Colorado's highways and byways does not end with the map drawers. Our archival collections trace the complex tale of how those roads came to be. Selected collections are suggested under Archives Highlights, and you can search further on our ArchivesSpace main page.