Most mountain bikers and hikers in Southwest Colorado will be intimately familiar with trail maps.

They will recognize the wavy contour lines, the dashed trails and the blue lakes and rivers.

But while maps are ubiquitous in outdoor recreation and travel, the mapmaking process and the cartographers who make them are often forgotten.

Cartography is an art in which mapmakers try to translate real-world information into a guide that anyone can use. It begins with geographic data and ends with the stylistic preferences of each mapmaker.

The process is almost entirely digital, with layers of information compiled into a single map. It can take months or hours depending on the purpose of the map, and each is ultimately driven by the interests of the cartographer.

“Maps are really, really important to easily and clearly communicate information,” said Farid Tabaian, owner of Singletrack Maps, which makes maps for mountain bikers and other trail users in Colorado. “(Cartography) is a vital tool.”

Mapmaking has changed as new technology has become available, but contemporary mapmakers rely on some sort of geographic information system (GIS) software to visualize data.

“That’s sort of your central development platform for creating a map. Everything is centered around the GIS software package,” said Will Jansen, owner of Centennial-based Outdoor Trail Maps, which produces maps for hikers and backpackers.

When creating a map, cartographers first find digital geographic data such as elevation or bodies of water and begin compiling them in GIS. That data can come from federal agencies such as the U.S. Geological Survey, states or local municipalities. Private companies like Google and ESRI, a map and data company, also have geographic data.

Both La Plata and Montezuma counties have GIS departments that have publicly available data such as roads and public land boundaries that cartographers can download and incorporate into their maps.

“When I’m making a topographic map, the first thing that I do is look at what elevation data is available,” said Anna Riling, owner of Durango’s Four Corners Mapping & GIS.

Once Riling has data, she can begin building the topographic contour lines, setting them for every 20-, 40- or 100-foot change in elevation.

Riling then layers other data on top, covering everything from roads and trails to vegetation, geology and the names of landmarks.

The purpose and audience of the map determine much of the data that a cartographer includes.

Travelers in a city will need street names, mountain bikers will need trail difficulty ratings and geologists will need different geologic strata.

The compilation of layers ultimately serves as the backbone of the paper map that hikers and bikers will then use.

“The reality is most of it is just sitting behind a computer,” Tabaian said.

Some cartographers like Jansen and Tabaian will take that initial map and test it in the field to check the accuracy of the underlying data.

“Place names (and) river information usually comes from government sources, but then a lot of it has to be totally revised and improved because either the information is out of date or it was inaccurate in the first place, and then it just has to be double checked,” Jansen said.

Jansen travels across the state or will enlist local friends to hike the trails he is mapping while wearing a GPS watch or carrying a GPS unit.

The GPS unit lays down a breadcrumb trail every few seconds as Jansen hikes, which he can later download to his GIS program and check against the original data.

Tabaian starts off most of his maps by venturing into the field.

The riding and hiking Tabaian, who was born and raised in Colorado, has done has not only collected trail data, but it has also allowed him to see the locations he is mapping.

“It’s certainly been an advantage to help us have a better understanding of the area before starting work on it,” he said. “You know the lay of the land.”

For some cartographers like Mark Stroud, who owns Moon Street Cartography in Durango and who counts many travel guide books among his clientele, accuracy is less of a concern.

“I don’t think accuracy really is an issue at the scale that we work,” he said.

Stroud may have to squeeze a map into only a few inches in a book about France, while Tabaian’s maps can extend a few feet when unfolded and cover a smaller area in more detail.

“I’m more concerned with the cartographic look, the feel (and) making sure it looks like every other map,” Stroud said.

When Stroud finishes layering the data he needs in GIS, he then transfers the map to graphic design software where it can be more easily molded and he can improve the visuals.

He has a strict style sheet that each map must follow for guide books. All of the fonts must be the same and the colors are standardized.

Other cartographers like Riling, Jansen and Tabaian also use graphic design software to finish their maps before they are sent to the printing press, but they have more creative discretion when stylizing their maps.

“A lot of artistic choice is how we get the maps to the final form,” Jansen said. “We spend a great deal of time focusing on creating styles for our map (like) nice hill shading (and) contours that are not too thick, not too thin, but readable.”

Cartographers can manipulate everything from the lengths of trail dashes to hill or “relief” shading, which creates the light and dark shadows and contrast that make the topography of a map pop. Color may seem inconsequential, but it’s something map makers constantly tweak.

As a former geologist, one of Riling’s maps visualizes the geology of popular trails in the Grand Canyon. Each layer of rock is a different shade of blues, purples, greens and reds to match the USGS’ official color chart.

The colors of her other maps are more subjective.

“I wish I could say that it’s an objective process, but I play around with the colors until I get something that I really like,” she said.

Riling even uses a website to see what her maps would look like for those who are colorblind.

“If you’re looking at a geologic map, the colors are a gradient. They’re distinct colors, but they’re not distinct enough to be told apart by someone with colorblindness,” she said. “You have to know that some maps are not going to be legible to everyone.”

Cartographers use their creativity and style to make more visually appealing maps, but they can also use them to change the information they convey.

“Our favorite term is ‘cartographic license,’” Tabaian said. “It’s basically the ability for the cartographer to tweak reality. If there’s a trail that has a ton of switchbacks, the cartographer can tweak that and maybe they don’t show as many. It’s a stylistic choice that generalizes the information to more clearly communicate it.”

With all design elements, the key is to mirror the landscape as closely as possible, Jansen said.

“The idea is to be able to visually correlate the terrain and the trail that you’re on with where you are in the real world,” he said. “Part of that is just having graphics on the map that invoke the right feeling.”

The time it takes to for each cartographer to make a map varies.

Stroud makes three to four maps each day and 400 to 500 annually because each guide book requires dozens of maps; the guide for the Canadian Rockies that Stroud just completed had 42 individual maps.

One of Riling’s maps for commercial production takes 40 hours or more, and with their field work, Jansen and Tabaian’s trail maps can take months from start to finish.

What makes Southwest Colorado special to map?

“The possibilities are endless,” Riling said.

For Tabaian, who made his first map of Durango, it comes down to the geography.

“It’s a fascinating area of our country,” he said. “… It’s a really fun area to map because of its uniqueness from the desert to the high mountains.”

ahannon@durangoherald.com