Using GIS to Map Fly Fishing Destinations

GIS Contributor


For more than written history, humans have been using fishing to put food on the table and pass time. The art of Fly Fishing, seemingly modern in terms of the required gear and techniques, has been around for more than a millennium.

Fly fishing began with simple curved needles, dressed in feathers and wax, attached to a stick. Anglers would use these together to dance the artificial fly to imitate the natural prey of fish. The concept hasn’t changed at all, but technology has evolved tremendously since the times of the ancient Roman and Japanese civilizations.

Since then, sticks have been replaced with finely engineered fiberglass; tangled horsehair replaced with neatly spooled synthetic line and leader; and weatherproof clothing now outfit anglers for greater success. Technology has allowed for higher success rates and longer outings through equipment, but one thing that has remained relatively the same is the art and skill of the sport.

A man standing in a river fly fishing.
William Bakemeyer Fly Fishing on the Colorado River.

Though angling mothers and fathers have been teaching sons and daughters the tips, tricks, and techniques to be successful, many still have a long learning curve to learn how to find and catch fish.

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For me, I began to fly fish in college with little to no idea what I was doing. My time in the aquatic classroom of the Cache la Poudre River began to surpass my time studying. Thankfully, I did end up with both my degree and an intimate knowledge of fishing that one river.

When it came time to start my military career in another state, my beloved hobby quickly died out as my frustration in unfamiliar waters grew. 

Even experienced anglers spend years learning to read the water in regions and those with less experience hire guides to take them to fishing hole destinations. So, when it comes to pick up and move, it takes time to learn nearby fishing streams or drop a decent amount of cash.

With little money for guides and even less time for building an intimate knowledge of the water myself. I looked for a better scouting solution; simply looking at blue lines on Google maps isn’t enough. Map reconnaissance became a habit during my experience in the military and I always wished that I had more mapping and intelligence on trout available to me.

As I continued my military education, I was introduced to Geographic Information Systems (GIS) and Geospatial Engineering. I immediately began brainstorming ways that I could apply this to fishing for trout in streams and rivers. 

Mapping For Trout

There are many free GIS programs available, but QGIS is the program that I used to create my map. I don’t want to spend any additional money on buying data, so it would all have to be open source; pulling data from government sources or what I could just find in a Google search.

 I had envisioned a topographic map that outlines rivers and streams in Colorado with known fish species, tributaries that may have trout, and real time data to support the ability to see the water temperature and stream flows.

The first few items would be easy enough to come by and combine to get a basic idea of what stretches of water I should go for. The real time data I knew would already be available; but what I had in mind might be recommendations and analysis that would help pick out what fly would be a good choice given the temperature of the water, time of day, and season. Basically, I wanted to “match the hatch” but have the computers do it for me. 

Many states around the nation have the data that I needed readily available online. Colorado Fish and Wildlife (CPW)Montana Fish, Wildlife, and Parks (Montana FWP), and Wyoming Game and Fish each have a data access page with great files available on many topics further than the basics of which streams have what species.

You can find data for restoration areas, big game, migration corridors, watersheds, etc. Each of the above state databases can be viewed in ArcGIS Online, but the data is available to use in QGIS or your favorite GIS software program. 

The United States Geological Survey (USGS) was my go-to resource for steam flow data. The USGS site has real time flow data that would help assess the discharge, gauge height, and temperature data to determine if the conditions are ideal for a fishing trip or not. Combining these files together helps us begin to paint a picture of a GIS application to help us find fish in places we may have no experience fishing.

A topographic map showing Cutthroat route locations.
QGIS Map for Cutthroat Trout by the author.

My personal fishing map of Colorado was coming together, but still felt like it could incorporate more information. I decided that if my created map came out to be a bust, I would at least like to know where the experts were in relation to fishing destinations.

Importing the locations of local fly shops was easy enough to access from Google Earth, then I added the hyperlinks to the shop’s webpage and local fishing reports. This is also a possibility for hyperlinking fly-fishing reports, like the ones posted on Orvis, to the rivers on a map. 

A detailed map showing a shaded relief area and a popup with attribute data about a fly fishing shop.
QGIS Map Zoomed into the famous Frying Pan River in Colorado. Note the Identify Results window is open to a local fly shop website. Map: William Bakemeyer.

Reviewing the new map I created, I was satisfied with a simple map that could narrow locations for fishing. However, I still want more, yet am limited by either the data availability or simply the data doesn’t exist.  

I envisioned  using imagery on rivers to identify prime locations to cast for trout. Near infrared imagery (NIR) may be able to identify possible areas of rivers where we find riffles and pools. Another potential tool would be topobathy, the combination of topographic Lidar (Light detection and ranging), and bathymetry, the measurement of the depth of water.

Topobathy could help us identify those prime fishing areas. Unfortunately, the USGS has very little existing data for topobathy, especially in the streams and rivers you find most trout fishermen. 

In the future, cost of acquiring these images may become more reasonable. But for now, we will be able to settle with the digital maps we have – a huge step compared to how Grandpa found his spots.

There are some options available to get this done. Colorado State’s DPW currently runs a fishing Atlas on their site. Here you can do most of the things that I had envisioned with my small attempt, but with even more features like fishing regulations, stocking information, boat ramps, and more. Best part? It’s free. 

For those who choose to support private enterprise there is a good app called Trout Routes. Trout Routes offers a free version with displays on stream gauges, stream lines, and fly shops, where the subscription offers stream classifications, access points, trails, and more.

I was able to make my own map that served the same purpose, but I think it’s worth the subscription to have it done already and done well. 

Technology will always continue to improve and give us a leg up on our how our ancestors did things. One thing that will never change is how we learn to read and interact with nature. Mapping tools, monofilament, and fine artificial flies all can help; but at the end of the day, just get out and go fishing. 

                                                                        Tight Lines! 

                                                                        By William Bakemeyer 

About the author

William is an Engineer Captain in the United States Army and pursuing a master’s degree in Geological Engineering from Missouri S&T. Born and raised in the small town of Kiowa, Colorado and graduated from Colorado State University with a Bachelor of Science in Construction Management. 


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