Big Thompson River Fly Fishing — Angler’s Guide

Anglers from all over the country are drawn to Big Thompson River fly fishing, a gem nestled in the beautiful front range of Colorado. Known for its scenic beauty and excellent trout fishing, the Big Thompson offers anglers a rewarding experience for novices and seasoned anglers alike. With its pristine Colorado fly fishing waters winding through breathtaking landscapes, Big Thompson River fly fishing provides anglers with a sanctuary for casting lines and connecting with nature. Whether you’re casting your line below Lake Estes or plying the scenic waters of Rocky Mountain National Park, the Big Thompson promises an unforgettable Estes Park fly fishing adventure.

Fly Fishing The Big Thompson River — A Guide For Anglers

From its scenic headwaters in Rocky Mountain National Park to the lower canyon below Lake Estes, the Big Thompson River beckons anglers with unparalleled experiences . Renowned for its exceptional water quality and abundant trout population, the Big Thompson stands as a testament to the enduring allure of Colorado’s pristine fly fishing rivers. As the lifeblood of Estes Park’s fly fishing scene, this iconic river offers anglers a smorgasbord of fishing opportunities, from its alpine vistas and meandering mountain meadows to its rugged canyons and deep plunge pools. With its diverse habitat and year-round accessibility, the Big Thompson River is a haven for fly anglers of all skill levels. Whether you’re a seasoned veteran seeking the challenge of stalking wild trout in remote backcountry streams or a novice angler eager to cast your first line, the Big Thompson provides quality experiences for all.

Year after year, anglers from across the country come to the Big Thompson River, drawn by its reputation as one of the premier fly fishing destinations in the West. And it’s no wonder why—the Big Thompson’s reputation for high-quality fishing is well-deserved, with its waters teeming with healthy populations of wild brown, brook, rainbow, and cutthroat trout. Whether you prefer to cast dry flies to rising trout in a high meadow stream or ply the waters in the lower canyon in search of trophy fish, the Big Thompson offers endless opportunities to hone your angling skills and create cherished memories on the water.

Different Sections For Big Thompson River Fly Fishing

The two distinct areas of the Big Thompson are the canyon section below Lake Estes and the Rocky Mountain National Park to the west of town. Each of which provide unique angling experiences and variability depending on the time of year, hatches, etc.

Lower Big Thompson River Below Lake Estes: The Big Thompson canyon offers breathtaking scenery and more secluded fishing spots. Accessible along US Highway 34 between Estes Park and Loveland, this section of the river provides anglers with year-round opportunities for great fly fishing. As the river flows downstream from Lake Estes, it carves its way through rugged granite cliffs, creating deep pools and fast riffles that hold abundant trout. Anglers can expect to encounter both wild and stocked trout in this stretch, with rainbow and brown trout being the most common species. The canyon’s cooler temperatures make it a comfortable fishing destination even in the heat of summer, and its proximity to Estes Park ensures convenient access to amenities and services for visiting anglers. Here are some notable options:

  • Mall Road: Accessible via Mall Road, this area below Lake Estes to the Waltonia Bridge spans approximately 9 miles and is designated as Catch and Release with artificial flies and lures only. Upstream of Mall Road is a public park, while below the bridge is well-marked private property. Although this section remains open year-round, it can become crowded, especially during peak seasons.
  • Highway 34 Pullouts: Traveling downstream along Highway 34, various pullouts provide easy access to the river, which parallels the road. While there is significant public access, it’s important to respect private property boundaries, which are well-marked.
  • Big Thompson Canyon: The river in the canyon features classic freestone stream characteristics, with pocket water dominating the landscape. Healthy populations of stoneflies, mayflies, and caddis support a robust trout population, primarily consisting of wild rainbows and browns averaging 10 to 14 inches.
  • Drake and Beyond: Below the Waltonia Bridge, the river continues through the town of Drake, where it merges with the North Fork of the Big Thompson. Moving downstream, the river’s gradient increases, offering more room for anglers seeking a quieter fishing experience. The Idlewild dam and lake provide additional fishing opportunities, although fishing in this stretch can be slow until reaching private property. Viestenz-Smith Park offers facilities and picnic areas but is generally less favorable for fishing. Further downstream, private property dominates, with limited access to what is termed the Narrows.
  • Narrows and Dam Store: The final four miles, or first four when traveling from Loveland, feature limited access due to private property ownership and the presence of the Narrows. While fishing in this area may be public, be mindful of access restrictions and the rising road that limits movement along the riverbank. The Dam Store, located at the mouth of the canyon, marks the end of this stretch of the Big Thompson River.

Upper Big Thompson River Fishing Access: The upper section of the Big Thompson is mostly located within Rocky Mountain National Park. While the fish aren’t as large as they are in the lower river below Lake Estes, they make up for it in the environment in which they reside. The high-altitude meadows, cascading waterfalls, plunge pools, and crystal-clear streams provide ideal habitat for trout, and the park’s strict conservation measures help maintain healthy fish populations. Anglers can enjoy the challenge of stalking wary trout in gin-clear water, surrounded by the sights and sounds of pristine wilderness. While access requires a park pass and some hiking, the unparalleled beauty and solitude of fishing in Rocky Mountain National Park make it a bucket-list destination for fly anglers seeking the ultimate Big Thompson River fly fishing experience. Here are some options:

  • Moraine Park: One of the most iconic Big Thompson River fly fishing destinations in Rocky Mountain National Park, Moraine Park offers anglers access to pristine waters teeming with wild trout. Located along Bear Lake Road and Fern Lake Road, Moraine Park features ample parking and well-marked trails along the road leading to various fishing spots. The river is meandering in nature, providing excellent pools and cut banks that are perfect holding lays for wild trout. It’s an idyllic setting for anglers who want the quintessential Rocky Mountain National Park fly fishing experience where you will be casting underneath towering mountain peaks with breathtaking views.
  • Forest Canyon: Nestled deep within the heart of Rocky Mountain National Park, Forest Canyon offers adventurous anglers the chance to explore the remote canyon riddled with pocket water and plunge pools. Accessible via the Fern Lake Trailhead, Forest Canyon rewards intrepid anglers with the opportunity to fish for wild brown, brook, and greenback cutthroat trout in a gorgeous canyon. While the fishing in Forest Canyon may be challenging, the breathtaking scenery and exceptional fishing make it a truly unforgettable Estes Park fly fishing experience.
  • North Fork Big Thompson: A tributary of the Big Thompson River, the North Fork offers anglers a quieter and more secluded fishing experience. Accessed via Hwy 43 and the Dunraven Trailhead, the North Fork Big provides anglers with the chance to fish for native trout in a remote and tranquil setting. While the lower portion of the North Fork has larger pools and often larger fish, the section in the national forest upstream provides some exceptional pocket water fishing.

The Best Time Of Year For Fly Fishing The Big Thompson River

Spring Fly Fishing On The Big Thompson River: As the days grow longer and the temperatures begin to rise, spring heralds the awakening of the Big Thompson River’s resident trout population. After a long, cold winter, fish are hungry and eager to feed, providing anglers with some of the best fishing opportunities of the year. The lower Big Thompson below Lake Estes comes alive during this season, offering anglers the chance to target large, hungry trout that haven’t seen much angling pressure for months. The most prolific hatches during spring include Blue Winged Olives (BWOs) and Midges, creating ideal conditions for fine dry fly fishing. While the upper section in Rocky Mountain National Park may be still frozen or affected by runoff from melting snowpack, with the right conditions, it can be magical.

Summer Fly Fishing On The Big Thompson River: Summer brings a bounty of opportunities for fly fishing Estes Park, with all sections of the Big Thompson River coming into their own. Popular hatches such as drakes, Pale Morning Duns (PMDs), stoneflies, and more make dry fly fishing particularly good during this season. Whether casting in the serene reaches of Rocky Mountain National Park or targeting big trout in the lower Big Thompson, anglers can expect exceptional quality throughout the summer months. The clear waters of the river provide ideal conditions for sight fishing, adding an extra layer of excitement to every cast.

Fall Fly Fishing On The Big Thompson River: As temperatures begin to cool and the days grow shorter, fall signals a shift in the behavior of Big Thompson trout. Fish are on the hunt for food, eagerly preparing for the long winter ahead, making for solid Big Thompson River fly fishing opportunities across all sections. While fishing in Rocky Mountain National Park may present some challenging situations due to low water flows, anglers who enjoy technical fishing will find the rewards well worth it. Below Lake Estes, mayfly and midge hatches continue to provide opportunities for dry fly fishing, while streamer and nymph fishing become increasingly productive. One of the highlights of fall fly fishing on the Big Thompson is the aggressiveness of brown trout as they prepare for spawning, offering anglers the chance to hook into some truly impressive specimens.

Winter Fly Fishing On The Big Thompson:
For those seeking solitude, winter fishing on the lower Big Thompson is not to be missed. While the upper section may be inaccessible due to freezing temperatures, the lower reaches of the river offer ample opportunities for dedicated anglers willing to brave the cold. With smaller flies and stealthy presentations, anglers can target large trout that are less pressured during this season. While winter fly fishing on the Big Thompson River requires careful attention to weather conditions and proper gear, the rewards of hooking into a trophy trout in a winter wonderland make it a truly memorable experience.

Recommended Gear And Fly Patterns

Depending on the section of river your fishing, any standard 4-5 weight fast-action fly fishing rod will do the trick. On any given day, you may be nymphing with two flies and split shot in the morning then single dry fly fishing in the afternoon. Having a rod that can cover all three primary techniques (dry flies, nymphing, streamers) will prove to be useful while fly fishing on the Big Thompson River.

In regards to flies, it can be difficult to have everything you need to be prepared for Big Thompson River fly fishing because every day is different depending on the time of year, weather, and current river conditions. But with the right foundation of flies in your fly box, you will be prepared for most situations that you experience on the water. Here are some highlights for flies that we would carry in our box that work most of the time:

Dry Flies

  • Midges: Griffiths Gnat, Smokejumper, Scottys Midge
  • Mayflies: Parachute Adams (various sizes), Blue Winged Olives (BWOs), Pale Morning Duns (PMDs), Tricos, Drakes
  • Stoneflies: Chubby Chernobyls, Royal Parachute X, Stimulators
  • Caddis: Elk Hair Caddis, X-Caddis, Emerger Caddis, Neversink Caddis


  • Midges: Zebra Midge, Mercury Midge, Brassie
  • Mayflies: Pheasant Tails, Hares Ears, RS2, Copper Johns, Lightning Bugs
  • Stoneflies: Pat’s Rubber Legs, Prince Nymph, Norfolk Special
  • Caddis: LaFontaine’s Deep Sparkle Pupa, Euro Peek-a-boo Caddis
  • Sow Bugs: Ray Charles, Pill Popper
  • Worms: San Juan Worm, Squirmy Wormy


  • Sculpin Imitations, Woolly Buggers, Sparkle Minnows, Zonkers

Important Tips and Regulations

Obtain the necessary fishing license from the Colorado Parks and Wildlife Department and familiarize yourself with the fishing regulations for the Big Thompson River. Practice catch-and-release to preserve the fish population and maintain the river’s ecosystem. Respect private property and follow any posted signs or restrictions.

In conclusion, the Big Thompson River stands as a testament to the unparalleled beauty and allure of fly fishing in Colorado. From its tranquil waters to the majestic peaks that frame its banks, every cast on the Big Thompson is an invitation to adventure and discovery. Whether you’re a seasoned angler seeking the challenge of stalking wild trout or a newcomer eager to experience the magic of fly fishing for the first time, the Big Thompson River promises unforgettable moments and cherished memories. Rocky Mountain National Park and Estes Park are truly blessed to be home to such a remarkable year-round fishery, and every angler who ventures to its banks is rewarded with a slice of angling paradise. So grab your rod, tie on your favorite fly, and plan your Big Thompson River fly fishing trip.

Experience The Big Thompson River With Kirks Flyshop

Want to have our Colorado fly fishing guides show you the best fishing spots for Big Thompson River fly fishing or maybe you want to take your family on a Rocky Mountain National Park tour? Book a guided Estes Park fly fishing trip with Kirks Flyshop and we’ll show you the way. From the best methods for catching trout in our area to seeing iconic destinations in Rocky Mountain National Park, let us show you why Estes Park is a top vacation destination for outdoor enthusiasts across the country.

Book your guided fly fishing trip with Kirks Flyshop!

From novices to seasoned anglers, we take guests of all skill levels and walks of life on our Big Thompson River fly fishing trips. Join us for a bucket list angling adventure and reserve your guide today.