Tanner & Morgan Barbeau, July 2025
Summer in Colorado is what fly angler dreams are made of. Rivers teem with prolific hatches for the dry fly purist. Streamer junkies can huck big, articulated flies in hopes of a toad. Reservoirs open to boats and the pursuit of toothy critters and other warmwater species. Mountain creeks run clear, full of eager and brilliantly colored brookies and browns. But the true crown jewel of Colorado summer fly fishing has to be the high alpine. Accessible for only a brief window each year, these rugged, awe-inspiring landscapes captivate the adventurous angler – and often (though certainly not always) reward their efforts with stunning fish that linger in memory long after the winter snow returns.
Colorado is home to more than 2,000 high mountain lakes above 10,000 feet—many of them perched above treeline at over 12,000 feet. This kind of altitude brings with it extreme conditions, fragile ecosystems, and often a demanding, sometimes treacherous, trek just to reach the water. And then, there are the unknowns. What starts as a bluebird forecast can quickly unravel into a wind-whipped, lightning-laced afternoon, forcing anglers to retreat to safer ground. Severe winters can cause the lake ice to grow so thick that dissolved oxygen is depleted, sometimes causing a winterkill, leaving little to no fish behind. But that’s all part of the adventure. In these harsh environments, there are no guarantees – and that’s exactly what makes it so special. Success isn’t measured only in fish caught, but in the experience itself: the challenge of the hike, the solitude, the scenery, and the chance to explore something wild and unpredictable.
If the harsh conditions and variability of the high alpine haven’t scared you off, read on. We’ll walk through how to boost your odds of success—covering gear, safety considerations, and tips for making your time in the backcountry both memorable and rewarding.
Morgan with a high alpine cuttie. The alpine can be tough but the rewards make it all worth it!
When to Fly Fish Colorado’s Alpine Lakes
The window to fish Colorado’s high alpine lakes is incredibly short. Even if the valley below is hitting summer temperatures in June, it’s not uncommon for higher lakes to remain frozen until July. Elevation and a lake’s orientation play a major role in the timing of ice-off. Every year is different, but generally, the alpine opens up in late June and winds down by mid to late September.
As with any fishery, insect hatches in alpine lakes are closely tied to water temperature. Right after ice-off, nymphing or throwing small streamers can be especially effective. As things warm up, hatches of midges, caddis, and small drakes become more common. Later in the summer, terrestrial insects take over as a key food source—so be sure to have hoppers, beetles, and ants in your fly box. Understanding the seasonal timing of these hatches will go a long way toward improving your odds.
Sunlight is another key factor in alpine lake fishing. Dawn and dusk are often the best windows to target cruising trout, when low light makes them feel safe enough to feed in the shallows—perfect for sight fishing. Overcast skies or a light wind chop can extend this shallow water activity, giving you more time to spot fish. But once the sun climbs high, fish usually retreat to deeper water where they can escape the light, and you’ll need to adjust your approach accordingly.
Alpine season also overlaps with Colorado’s monsoon season, which typically brings afternoon thunderstorms, gusty winds, and fast-changing conditions. Weather forecasts in the high country are famously unreliable, so even on a clear-looking day, it’s wise to pack layers, bring a rain jacket, and bail quickly if the skies turn. When storms roll in, getting below treeline quickly can be the difference between a close call and a dangerous situation.
Fly Rod & Line Setup for High Alpine Lakes
Everyone has different preferences when it comes to their rod and line setup for a high alpine lake. We’ve found that a 9’ 5wt rod and floating, weight forward line covers most situations effectively. If you have access to one, packing an extra spool or reel with an intermediate or sink-tip line can be a big help when targeting deeper drop-offs or cruising fish that aren’t feeding near the surface.
Our go-to high alpine lake rod has to be the Douglas DXF Gen 2. Its moderate-fast action offers the versatility to throw streamers into alpine wind while still allowing for the delicate presentation of dries and dry-dropper rigs. It’s lightweight, breaks down into four pieces, and carries easily on long hikes—making it a solid choice for backcountry missions.
The Douglas DXF Gen 2 is perfect for all high alpine applications, and is lightweight enough to pack in or just carry along the hike.
When considering leaders, it’s best to air on the lengthier side. Most alpine lakes hold gin clear water, so creating some extra distance between your flies and the fly line will work in your favor. We typically fish a 4-6X 9-12ft leader for dry flies and nymphs, and thicker, 0-2X 7.5ft fluorocarbon leader for streamers. Depth can play a big role here, so take some time to do a lap around the lake to observe what the fish are doing and choose your rig accordingly.
Best Flies for High Alpine Lakes
A messy but quite full alpine box. It’s always good to have a variety of colors and sizes.
It’s good to have an array of flies with you on your alpine adventure. Here’s a short list of some of our go-to alpine flies we always have on hand, ideally in a variety of sizes and colors where applicable:
Dry Flies (size 16-20)
- Elk Hair Caddis
- Parachute Adams
- Ants & Beetles (Hippie Stomper is a favorite)
- Griffith’s Gnat
Nymphs (size 16-22)
- Hare’s Ear
- Pheasant Tail
- Zebra Midge (black, brown, tan, red)
- Copper John
- Chironomids (Ice Cream Cone)
- Scuds (orange, gray, olive)
Streamers (size 6-10)
- Woolly Bugger (olive, black)
- Mini balanced Leeches (olive, black, burgundy, purple, brown)
- Meat Whistle (olive, black, tan)
Tactics & Presentation
For many anglers, the biggest draw of the high alpine is the dry fly fishing. While Colorado’s high lakes are stocked with a variety of trout species, many hold cutthroat trout—and the males are hard to miss. Their firetruck-red flanks glow in the clear water, and watching one rise and slurp a dry off the surface is an unforgettable, addictive experience. If that’s your style, it’s worth doing a few laps around the lake to locate cruising fish and sight-fish to them.
One of our favorite rigs for this is the dry-dropper. It lets you fish both the surface and just below it—imitating an emerging insect or one stuck in the film. A tan or black Hippie Stomper with a small zebra or sparkle midge 12″–18″ below is our go-to. This setup is great for targeting trout cruising the shallows or the fish out in the deeper water suspended near the surface.
Trout also love to cruise deep drop-offs. These edges give them quick access to both shallow feeding zones and deep, cool refuge. These areas are productive with either a dry-dropper or a full indicator rig. We often fish a chironomid and a balanced leech 18″–24″ apart, suspended just a foot or so off the bottom. Dialing in your depth is key—spend time experimenting until you find what works.
Streamers can also be incredibly effective in the alpine, especially for larger fish holding deep. A small Woolly Bugger or Meat Whistle fished on a sink-tip or full-sink line can pull aggressive strikes. The key is to let your fly sink fully before retrieving. Try both short, quick strips and longer, slower pulls. Some anglers also like to add some split shot 2–3 feet above the fly to change the movement slightly. As always—mix it up and see what gets a response.
Streamers on a sink tip or full sink line can provoke strikes from large fish holding in the depths of the lake.
Fly Fishing in the Elements
As mentioned, the high alpine is both breathtaking and unforgiving. Wind is almost always a factor—and if it’s calm when you arrive, chances are it won’t stay that way. To stay effective in changing conditions, it’s helpful to have a few different casting techniques in your toolkit. The double haul, in particular, is key for punching through strong winds. If you’re not already comfortable with it, it’s worth practicing before your trip.
You may also run into situations where backcast room is limited. Many alpine lakes are ringed by steep scree fields or dense brush, and a standard backcast can easily result in snapped-off flies and tangled line. In these cases, try stopping your backcast higher to keep the line clear—or better yet, make sure you’re familiar with the roll cast, which requires little to no space behind you and can still deliver a clean, accurate shot.
Stealth is just as important as presentation when fishing high alpine lakes. How you move around the water can make or break your chances. Take it slow. Approach the shoreline with caution, keep your rod low, and treat it like a hunt—because it is. In these crystal-clear lakes, trout are often extremely wary and can spook at the slightest movement or flash.
Wearing clothing that blends into the natural environment—light blues, grays, and greens—can help you stay less visible against the sky and rock. The more invisible you are, the better your chances. Staying quiet, deliberate, and observant will go a long way in turning sightings into eats.
Must-Have Fly Fishing Gear in the Backcountry
Packing for a high alpine fly fishing trip is a little different—mainly because you’re carrying everything on your back. Comfort and efficiency matter, both on the hike in and while you’re fishing. Here are a few essentials we never leave behind:
Fly rod & reel (duh): Whatever setup you choose, ideally your rod breaks down into four pieces so it can fit in a tube or sock and strap easily to your pack. Trails up to these lakes are often lined with brush and branches just waiting to grab a rod tip, so it’s usually best to pack it away until you reach the lake.
Compact fly box: You don’t need to bring your entire fly collection—just a small box with a solid variety of alpine staples (like the ones mentioned above). A few of each pattern in different sizes is smart. The last thing you want is to lose the fly that’s working and not have a backup.
Floatant & dry shake: If you’re fishing dries, floatant will help them ride the surface longer, especially right out of the box. Once they’ve been eaten a few times, they tend to sink—so having dry shake to revive them is a game-changer.
Nippers & hemos: Basic tools for cutting tippet, pinching barbs, and safely removing flies from a fish’s mouth.
Extra leaders & tippets: It’s a good idea to bring 1–2 extra leaders (typically 4–6X) and a few spools of tippet. We typically pack nylon (floating) in 5X and 6X, and fluorocarbon (sinking) in 3X-6X for subsurface presentations.
Split shot: Not essential, but useful—especially when fishing streamers. A small split shot 2–3 feet above the fly can add some extra weight and a different movement in the water column.
Net: A lightweight net makes handling fish safer and easier. These trout live in a tough environment already, so keeping them in the water while unhooking goes a long way in reducing stress.
Non-fishing essentials to pack:
Extra layers: Temps can swing fast—bring a warm midlayer and something wind-resistant.
Rain jacket: A must-have, even if the forecast looks clear.
Quick-dry pants (or rain pants): Wet legs make for a miserable hike out.
Rain fly or waterproof backpack: Keep your gear dry if the skies get dark.
Extra socks: Wool socks are a great quick-drying, blister-resistant option.
Camp shoes: Lightweight, comfy shoes give your feet a break at the lake.
Water purifier: Essential if you run out of water and need to refill from the lake or nearby stream.
Sunscreen & bug spray: The sun and bugs can both be relentless up high.
Bear spray: Especially important in areas with known wildlife activity—check local regulations.
Snacks: More than you think you’ll need. High-alpine hiking burns calories fast.
Fire starter: For emergencies—it’s always better to have one and not need it.
Garmin or satellite communicator: Cell service is rare, so bring a device to check in or call for help if needed.
Safety in the High Alpine
The high alpine is one of the most stunning places you can fish—but it’s also one of the harshest. A few extra safety and environmental precautions can go a long way in keeping you safe and preserving these fragile ecosystems.
Altitude awareness:
There’s a reason it’s called “high alpine.” The elevation can take a serious toll on your body, especially if you’re coming from lower altitudes. The air is thinner, which means less oxygen and harder hiking. Take it slow, hydrate constantly, and don’t be afraid to take breaks. Altitude sickness is real and can become dangerous quickly if ignored. Being higher up also means you’re much closer to the sun, so regular sunscreen application is essential to avoid serious burns.
Weather preparedness:
Alpine weather changes fast. Wind, rain, hail—even snow—can roll in with little warning. No matter how warm it is when you start your hike, pack extra layers and a rain jacket. Being prepared to pack up and drop below treeline quickly can make all the difference in staying safe and warm.
Download offline maps:
Even if you’re familiar with the area, downloading an offline map of the wilderness zone you’re heading into is a smart move. Cell service is often unreliable or nonexistent in the high country, and having a GPS-enabled map on your phone can be a lifesaver. In an emergency, it makes it much easier to communicate your location, share coordinates, or identify alternate routes out. Apps like Gaia GPS, OnX Backcountry, or even Google Maps (with offline mode enabled) can give you peace of mind—and a backup plan when you need it most.
Wildlife awareness:
Colorado’s alpine is home to an incredible range of wildlife—black bears, moose, marmots, pikas, mountain goats, and more. Stay alert, keep a safe distance, and if you’re camping overnight, use a bear canister and store food properly. Always follow Leave No Trace principles: pack out everything you pack in, stay on durable surfaces, and avoid disturbing wildlife. Your small actions help protect these delicate areas for future generations.
Weather can flip quickly, be ready to head to lower elevations at a moment’s notice.
Fishing Ethics
A few simple habits can ensure you’re fishing responsibly in these sensitive, high-country waters.
Use barbless hooks:
Catch and release is the norm in most alpine lakes, and barbless hooks are essential. Trout have especially delicate mouths, and barbs can cause irreversible damage—not to mention make fly removal harder and more stressful for the fish. Always check your flies before casting. If they’re not barbless, take 5 extra seconds to flatten the barb with your hemostats.
Respect spawning fish:
While trout in alpine lakes may not always be able to spawn successfully due to habitat limitations, many still exhibit spawning behavior shortly after ice-off. It’s important to respect this process regardless of success rates. Look out for paired-up fish following each other, females guarding redds (light-colored patches of cleared gravel), or clusters of fish near lake inlets flashing and rolling. These fish are expending serious energy, and the added stress of being hooked can be fatal. Instead, target fish that are actively cruising and feeding—it’s more ethical, more challenging, and ultimately more rewarding.
Final Thoughts
Don’t forget to stop and take in the views every once in a while.
Fly fishing in Colorado’s high alpine lakes isn’t just about catching trout—it’s about immersing yourself in some of the most remote, beautiful, and wild landscapes the Rockies have to offer. These places demand effort, patience, and respect. The hike might test you. The weather might change on a dime. The fish might not always cooperate. But that’s all part of the magic.
If you come prepared, stay present, and fish with intention, you’ll walk away with more than a full net. You’ll earn moments of true solitude. You’ll witness nature at its most raw and vibrant. And if you’re lucky, you’ll have a few unforgettable eats burned into your memory to carry you through the off-season. So pack smart, tread lightly, and embrace the adventure. The alpine is waiting.
Morgan & Tanner Barbeau are fly fishing guides and Douglas Pros in the Arkansas River Valley of Central Colorado. When they aren’t busy guiding, they’re fishing their home waters, exploring new areas, and filming their adventures for their brand, Mop Fly Productions.