Winter Fly Fishing Tailwaters in Colorado | Big Thompson River & Estes Park Guide

Big Thompson Tailwater (Below Lake Estes)

The Ultimate Guide to Winter Fly Fishing Tailwaters in Colorado and the Rocky Mountains

When most people think of fly fishing in Colorado, they picture sunny summer afternoons, dry flies dancing on the water, and trout rising with abandon. But ask any seasoned angler around Estes Park or the Front Range, and they'll tell you a little secret: winter and early spring are some of the best times to fish Colorado's tailwaters.

Here at Lost Outfitters, we live for those crisp winter mornings when the rivers are quiet, the crowds are gone, and the trout are still very much feeding. And there’s no better place to experience this than right here on our home water—the Big Thompson River below Lake Estes.

In this guide, we're diving deep into everything you need to know about winter tailwater fishing in Colorado, with a special focus on the incredible tailwater right here in Estes Park. So grab a cup of coffee, get cozy, and let’s talk trout.

What Makes Tailwaters So Special in the Winter?

If you’re new to winter fly fishing or just hearing about “tailwaters,” here’s the rundown. A tailwater is the stretch of river directly downstream from a dam. These rivers are special in winter because the water being released from the bottom of reservoirs is relatively stable in both temperature and flow. This creates an environment where trout can remain active and feeding, even when surrounding freestone rivers are iced over and shut down.

For us here in the Rocky Mountains, tailwaters mean year-round fishing. No off-season. No waiting for runoff to subside. Just cold, clear water and hungry trout.

Spotlight on the Big Thompson Tailwater (Below Lake Estes)

If you’re looking for a reliable winter fishery close to Denver, Boulder, or Fort Collins, it’s hard to beat the Big Thompson tailwater below Lake Estes. And since this is right in our backyard, it’s a river we fish and guide on almost daily during the winter months.

What to Expect Fishing Below Lake Estes

The Big Thompson tailwater flows right out of Lake Estes Dam and meanders down through Estes Park before heading into the canyon. Thanks to the consistent releases from the dam, this section stays ice-free throughout most of the winter and provides some of the best opportunities to target trout during the cold months.

Here’s what makes it so special:

• Consistent Flows: Even in the dead of winter, flows typically hold steady between 20-100 CFS, creating perfect nymphing conditions.

• Water Clarity: Winter often brings crystal-clear water. This is beautiful, but it means stealth is key. Approach runs quietly, use long leaders, and lighter tippet like 6x.

• Midge Hatches: Believe it or not, even when it’s snowing, you can find trout rising to tiny midges. On warmer afternoons, we’ll fish Griffith's Gnats or Cluster Midges to pods of sipping rainbows.

• Healthy Trout: This section holds an impressive mix of rainbow and brown trout, with plenty of fish in the 12-18 inch range, and the occasional bruiser that'll test your light winter tippet.

Where to Fish

We spend a lot of time guiding between Olympus Dam and the outskirts of town. This stretch is easily accessible, and the trout tend to stack up in the slower, deeper pools during winter. Look for:

• Soft seams along the bank.

• Deeper runs where the current slows.

• Tailouts below riffles, where food naturally collects.

And if you're unfamiliar with the area or reading the water feels intimidating, that's exactly why we offer guided trips—we know where the fish are hiding.

Winter Fly Selection Below Lake Estes

Fly selection doesn’t have to be complicated. In fact, winter fishing often simplifies things because the trout are keyed in on a few reliable food sources:

Midges (Size 20-26)

These are the bread and butter of winter fly fishing. Think:

• Black Beauties

• Zebra Midges

• Top Secret Midges

Baetis (Blue Winged Olives) (Size 18-22)

Especially on overcast days, Baetis patterns like:

• RS2s

• Juju Baetis

• WD-40s

Egg Patterns

During the late winter and into early spring, rainbow trout start thinking about spawning. Egg patterns in peach, pink, or orange can work wonders as an attractor fly.

Winter Dry Fly Action

If you catch a warmer day, keep an eye out for fish rising to clusters of midges. Have a few:

• Griffith’s Gnats

• Parachute Adams (for imitator purposes)

Pro Tip: Run a double-nymph rig under a small indicator. Think egg + midge, or Baetis + midge, with enough weight to get down deep.

Gear Recommendations for Winter Tailwaters

When it comes to winter fishing, your gear can make or break your day:

• Rod: A 9’ 4wt or 5wt is ideal for delicate presentations.

• Reel: Smooth drag, because 6x tippet doesn’t forgive much.

• Waders: Insulated or thick base layers underneath.

• Boots: Studded soles help on icy banks.

• Clothing: Dress in layers. Merino wool base layers, fleece mid-layers, and a windproof, waterproof outer shell.

• Accessories: Bring hand warmers. You’ll thank us later.

Be Ready for Anything

Winter in Estes Park is unpredictable. One minute it’s sunny and 40 degrees, the next a snow squall moves through. Be prepared for changing weather and don’t push your limits on icy banks. And always, always check flows and forecasts before heading out.

Why Book a Winter Trip with Lost Outfitters?

Fishing in winter can be intimidating. The water is cold, the bugs are small, and the fish are extra spooky. But that’s where we come in. At Lost Outfitters, our experienced guides take all the guesswork out of the day so you can focus on fishing, learning, and soaking in the beauty of Rocky Mountain National Park in its quietest, most peaceful season.

Whether it’s your first time fishing tailwaters or you're chasing that trophy winter trout, we’ve got you covered.

Let's Fish This Winter!

If you're looking for a guided fly fishing trip in Estes Park this winter or early spring, we’d love to show you why tailwaters like the Big Thompson below Lake Estes are so special.

👉 Contact us with any questions!

Winter doesn’t mean fishing has to stop. In fact, some of the best days on the water happen when there’s snow on the banks and midges in the air.