Nestled in Park County below the Eleven Mile Reservoir Dam, this section of the South Platte embodies everything that makes fly fishing in Colorado special. Majestic canyon scenery, easy access, and an abundance of large, healthy trout make it a favorite destination for anglers from near and far.
Colorado is renowned for its exceptional tailwater fisheries—those highly productive stretches of river located just downstream of dams. These unique waters provide ideal conditions for trout, and the South Platte River in Eleven Mile Canyon is no exception.
However, with accessibility comes heavy fishing pressure. The trout in Eleven Mile Canyon are among the most educated in the state—able to recognize fly patterns with uncanny precision. Like the renowned Gold Medal stretches of the South Platte in Cheesman Canyon and the “Dream Stream” near Hartsel, the river in Eleven Mile Canyon offers some of the most technical fishing in Colorado. Success here demands that anglers bring their A-game, using light tippets, tiny flies, and a careful, deliberate presentation.
Aquatic insects are abundant in Eleven Mile Canyon, which provide a rich food source for trout to grow quickly. Mayflies, midges and caddisflies are all present and hatches vary by season. Scuds, a common staple in a trout’s diet, are present year-round.
Thanks to consistent water temperatures below the dam, this fishery offers year-round opportunities for those hardy enough to face the chill of winter.
Special Fishing Regulations
The Quality Waters segment encompasses 3.8 miles of the South Platte River, extending from the Eleven Mile Reservoir Dam downstream to the Wagon Tongue Gulch Road bridge at Spring Gulch.
To manage fishing pressure and protect the health of the fishery, Colorado Parks and Wildlife has designated this reach as catch-and-release only, with fishing limited to artificial flies and lures.
Fishing regulations on the South Platte vary farther downstream, and anglers should consult the Colorado Fishing Regulations Brochure before fishing in other locations.
In addition to the purchase of a Colorado fishing license, Eleven Mile Canyon is managed by the U.S. Forest Service and requires anglers to purchase a day-use pass to enter the area.
Fish Populations and Species
As part of its statewide fishery management efforts and participation in the Quality Waters program, Colorado Parks and Wildlife conducts regular surveys to monitor and manage fish populations across the state’s lakes and streams.
These surveys collect valuable biological data—often through methods such as electrofishing—to track population trends, evaluate the success of management actions like fish stocking and guide future management goals. The information gathered enables biologists to make informed decisions about fishing regulations, stocking strategies and conservation priorities that sustain Colorado’s world-class fisheries.
Past surveys in Eleven Mile Canyon have shown that the river supports excellent populations of brown, rainbow, and cutbow trout (a rainbow–cutthroat hybrid). Most fish average between 12 and 17 inches in length, with some impressive specimens exceeding 20 inches.
“Every indication is that this area continues to support good fish populations,” said CPW Aquatic Biologist Kira Paik. “Our most recent surveys have shown populations have continued to do well, with densities as high as 184 fish greater than 14 inches in length per acre, and estimates of 1,305 trout six inches or greater in length per mile.”
Paik added, “In addition to the solid trout population numbers, Eleven Mile Canyon is one of the few populations of rainbows in the South Platte drainage where we see successful natural reproduction due to manipulation of flows thanks to the cooperation of Aurora Water and Denver Water.”
Fishing Eleven Mile Canyon
In this Quality Waters profile video, angler Elisa Gleason shares why the South Platte River in Eleven Mile Canyon has become one of her favorite fly-fishing destinations. A passionate advocate for getting more women involved in the sport, Gleason describes how fly fishing quickly evolved from a casual pastime into a full-blown obsession. She also offers valuable tips for tackling the “technical waters” of the canyon, where trout are known for being both wary and selective.
Hatcheries and Stocking
Colorado’s Quality Waters fisheries are the result of decades of scientific research, habitat restoration, conservation management, and carefully planned hatchery and stocking programs.
Stocking plays a vital role in maintaining sustainable fish populations and ensuring that quality recreational fishing opportunities continue into the future. While some waters support limited natural reproduction, most lack the habitat and environmental conditions necessary for fish to successfully spawn and sustain their populations. Even in systems where natural reproduction occurs, recruitment—the number of juvenile fish that survive to adulthood—can be lower than desired to support consistent angling opportunity. Whirling disease, a parasitic disease primarily affecting trout and salmon, has also impacted wild trout populations in many areas.
Since 2020, Colorado Parks and Wildlife has stocked more than 37,000 trout into the South Platte River in Eleven Mile Canyon to supplement natural populations and enhance fishing opportunities for anglers.
“Our primary objective with stocking the South Platte in Eleven Mile Canyon is to supplement the naturally reproducing population of wild rainbow trout that people enjoy catching,” said Paik. “Efforts have focused on stocking whirling-disease-resistant-strains of rainbow trout in hopes the populations will incorporate those helpful genetics into the future.”
Collaborative Conservation
In October 2023, the Lake George diversion dam, located at the entrance to Eleven Mile Canyon, was removed to restore the river to more of its natural state. Originally built in 1952 to divert water, the dam had been inactive for decades. The outdated structure hindered fish passage and disrupted the river’s natural flow and sediment transport.
This ambitious restoration project was a collaboration among state, federal, and local partners. Key participants included Colorado Parks and Wildlife, Trout Unlimited, U.S. Forest Service, Colorado Water Conservation Board, Colorado Springs Utilities, Coalition for the Upper South Platte, and Jacobs Solutions Engineering, among others.
The dam removal project had numerous benefits to the overall health of the river’s ecosystem and fish populations. “Removing artificial dams can improve the river by restoring the natural functions of the river and allowing fish to move upstream and downstream more easily,” said Paik. “This allows fish to access important resources that can improve their chances of survival and ability to complete their life cycles.”
Learn More
The South Platte River in Eleven Mile Canyon is just one of more than 50 locations featured in Colorado Parks and Wildlife’s new Quality Waters program. To learn more and to see other locations, please visit CPW’s website.
