5 Types of Trout You Can Catch in Colorado Waters

Known for its stunning mountain landscapes and clear waters, Colorado is a haven for fly fishing enthusiasts and outdoorspeople alike. With most Colorado fisheries situated along I-70 and in the Rocky Mountain valleys, anglers can easily access destination-level fly fishing. 

Colorado is home to a diverse array of freshwater species, including bass, panfish, and trout. As fly fishing revolves around the fly-to-fish food chain, trout are the most sought-after species of freshwater fish among Colorado fly fishing guides and anglers alike. Here, we will explore some of the iconic trout species and sub-species that inhabit Colorado’s waters and how you can identify them.

Trout Biology — An Overview for Identification

Trout are a type of freshwater fish belonging to the salmon family. They are typically found in cold, clear, moving water. Compared to other freshwater species, such as bass and panfish, trout have tiny scales that help them propel through the water at high speeds. Instead of large scales as “armor,” trout secrete a slime coat, which protects them from abrasions and infections and lubricates their bodies for optimal movement. 

Trout also lack spines in their fins and have a small adipose (fatty) fin along their back near their tail. Researchers theorize that the lack of spines and additional fin is an evolved trait that helps trout stabilize and sense water flow. While trout’s tails provide the strength required for propulsion, their lower front fins serve as the up and down steering mechanisms while their pelvic fins sit back on their body, on each side of their anus, for left and right balance. 

Colorado’s waters provide some of the most perfect conditions for trout to exist. With many places for trout to school and thrive throughout the U.S., multiple trout subspecies have evolved to meet favorable conditions in America’s riverways — eventually making their way into Colorado’s rivers. 

Rainbow Trout

Known for their vibrant colors and easily identifiable pink stripe, rainbow trout are a very adaptable species of trout that thrive in various waters throughout Colorado. As one of the most common types of trout in Colorado, rainbow trout can be found in almost every river and stream and are typically stocked in large lakes or reservoirs throughout the year. 

Contrary to popular belief, Rainbow trout are not native to Colorado. As they began their journey eastward from the western Canadian coastline, sport fishing and farming for food have introduced them to worldwide waters. Rainbow trout provide an exciting opportunity for anglers. They can put up a good fight and range in size, weighing an average of four to eleven pounds. 

Cutthroat Trout

As the state fish of Colorado, cutthroat trout are undoubtedly the crown jewel of Colorado’s fisheries. Distinguished by the red “slash” marking on the underside of its lower jaw, cutthroat trout are a fun catch for anglers looking to check another box off their species bucket list. Cutthroat trout come in various subspecies, all native to waters west of the Rocky Mountains. 

Colorado is home to three subspecies of cutthroat trout: the greenback, the Rio Grande, and the Colorado cutthroat. In 1994, the greenback cutthroat trout was named Colorado’s state fish. As native habitats decrease in quality due to warmer temperatures and urbanization, Colorado Parks and Wildlife Services has started implementing extensive recovery efforts to preserve native cutthroat species. Due to hybridization, pure greenback cutthroat trout are rare when fishing in Colorado. 

Cutbow Trout

A cutbow trout is a hybrid species of a rainbow trout and a cutthroat trout. As an interspecific fertile hybrid, cutbow trout were created as a result of female cutthroat egg fertilization by male rainbow trout. These hybrids are typically characterized by the distinctive red cutthroat slash under the jaw with the characteristic pink rainbow trout stripe along the body. Cutbow trout hybrids can often be confused with pure rainbow and cutthroat species as they can take on stronger traits with multiple instances of hybridization. However, cutbows can typically be identified by their white-tipped fins.

As a fertile trout hybrid, cutbow have become a popular catch in Colorado’s riverways and have evolved to withstand changing environments, growing up to 30 inches under favorable circumstances. Cutbow are known for their aggressive feeding habits and impressive size, making them an exciting and favorable catch for anglers. 

Brown Trout

The brown trout was first brought into Colorado in the 1890s and is abundant in the cold high-mountain streams and rivers. Different in appearance from rainbow, cutthroat, and cutbow trout, brown trout can range in color from a light silvery brown to a golden brown, with a dark back and light-colored belly. Depending on their environments, brown trout often have spotted markings, typically consisting of black, red, and orange spots encased in a light or pale-colored halo. 

Known for their intelligence and fighting abilities, brown trout are a favorite amongst experienced anglers. They can often be found in deeper pools along Colorado’s rivers and streamways. Because the brown trout is a highly intuitive species, they can often detect the difference between a real fly and an artificial one. Catching a brown trout is a true testament to an angler’s patience, skill, and abilities and is often lauded as a big accomplishment for new anglers. 

Brook Trout

The smallest of the Colorado trout, the brook trout, is an abundant species typically found in higher-elevation lakes, dams, and streams. Brook trout have a dark green to olive-brown color on their back with intricate worm-like patterns in lighter shades on the top half of their body. On their lower half, they can have red or orange spots with a blueish halo around them with a dark orange or red-brown belly.

As opportunistic feeders, brook trout often rise to the water’s surface to feed, making them an exciting species for anglers. Because they tend to inhabit clear water, bright-colored clothing can easily spook them. Utilizing stealthy fishing approaches and precise fly presentations are key to catching a brook trout.

Trout Conservation and Colorado Anglers

As climate changes and environmental pressure impact Colorado’s waterways, protecting the trout population is becoming increasingly important for anglers. By understanding the types of trout present in Colorado and maintaining the delicate balance between nature and human involvement, anglers can do their part to sustain fishing resources for all to enjoy. 

Whether you’re a seasoned angler or a beginner, Colorado offers many opportunities for people to experience the thrill of trout fishing. Before heading out to experience one of Colorado’s pristine waters, visit Fly Fishing Outfitters in Vail Valley for expert advice on all things fly fishing. 

Our Orvis-endorsed fly fishing guides are the experts on fish identification, sustainability, and conservation. By utilizing catch-and-release practices, Fly Fishing Outfitters is committed to preserving Colorado’s waters while preserving the art of fly fishing for generations to come. If you’re looking to complete your species bucket list or want to experience the thrill of the catch, visit our fly shop in Avon or schedule a guided fly fishing trip with one of our experts today!