Big Thompson River Fishing ReportRead full report at Rocky Mountain Anglers
Big Thompson River
39.3 CFS
59°F
Well Below Normal
63°F
Insights
Water 59°F — prime
Wind 2 mph — calm
Low flows at 39.3 CFS
The Big Thompson is the Front Range's most accessible wild-trout tailwater, and it fishes almost entirely from the road. Below Olympus Dam at Lake Estes the river drops east into the Big Thompson Canyon along US-34 toward Loveland, so you can pull into a gravel turnout, step down the bank, and be nymphing pocket water in a couple of minutes. The dam gives it a steadier, colder, more consistent flow than a true freestone — the gauge below Lake Estes sat around 100-125 CFS through summer 2026 — but the character is pocket water, plunge pools, and fast riffles rather than a broad glassy tailwater. The trout are wild rainbows and browns, mostly 10-14 inches; the canyon stretch hasn't been stocked since the mid-1990s, and the fish hold in every seam and behind every rock.
It fishes as a technical small stream more than a big-water river. This is dry-dropper and tight-line nymphing water: a terrestrial or attractor up top with a pheasant tail, hare's ear, or small caddis a foot or two down works most of the year. The bugs run small — midges and Blue-Winged Olives dominate spring and fall, with caddis, PMDs, Yellow Sallies, and stoneflies filling in summer, and tricos and terrestrials by late summer. It's all wadeable; nobody floats the Big T. The trade-off for the easy access is company: the canyon turnouts get busy on summer weekends and the fish see a lot of flies, so the catch-and-release stretch just below the dam and the water a short walk from the pullouts fish better than the obvious runs right at the road.
The context that shapes this river is the September 2013 flood, which tore through the canyon. The high water itself did surprisingly little to the trout, but the emergency road and bank repairs that followed hammered the habitat. A multi-year stream-restoration effort — one of Colorado's largest — rebuilt channel and habitat through the canyon, and CPW restocked to jump-start recovery; populations are now near or at pre-flood levels, and the upper reaches between Drake and Estes Park (which never needed rebuilding) match or exceed old estimates. Beyond the canyon there are two other fisheries worth knowing: the small, brushy North Fork joining at Drake, and the headwater meadows and pocket water inside Rocky Mountain National Park (Moraine Park, Forest Canyon), where the fish are smaller but the setting is the draw.
Fishing Reports
Species
- Brown Trout
- Rainbow Trout
- Brook Trout
- Cutthroat Trout
| Species | Abundance | Best Season | Size | Notes |
|---|---|---|---|---|
| Brown Trout | Primary | Sep-Nov | 10-16" | The dominant wild species in the canyon. Fall pre-spawn browns are the best shot at a larger fish — swing or strip streamers through the deeper plunge pools. |
| Rainbow Trout | Common | May-Oct | 10-14" | Wild population in the catch-and-release canyon stretch, not stocked here since the mid-1990s. The lower river through Loveland also holds stocked put-and-take rainbows. |
| Brook Trout | Limited | Jun-Sep | 6-11" | Common in the RMNP headwaters and the brushy North Fork above Drake. Small but eager — a good target on small dries when the mainstem is crowded. |
| Cutthroat Trout | Limited | Jul-Sep | 6-12" | Greenback/cutthroat in Rocky Mountain National Park's upper meadows and tributaries. Catch-and-release for cutthroat under park rules. |
Sections
North Fork Big Thompson — at Drake
WadeBrook Trout · Brown Trout · Rainbow Trout
The Narrows / Lower Canyon — Waltonia to Cedar Cove
WadeBrown Trout · Rainbow Trout
Lower Big Thompson — Canyon Mouth through Loveland
WadeBrown Trout · Rainbow Trout
Rocky Mountain National Park — Moraine Park & Forest Canyon
WadeCutthroat · Brook Trout · Brown Trout · Rainbow Trout
The Canyon — Below Lake Estes (C&R)
WadeBrown Trout · Rainbow Trout
Regulations
A designated Wild Trout catch-and-release stretch runs from the outlet of Lake Estes (Olympus Dam) downstream to the Waltonia Bridge — artificial flies and lures only, all trout released. The rest of the canyon and the lower river fish under standard statewide Colorado trout regulations; Rocky Mountain National Park headwaters carry their own park rules.
Access & Logistics
Getting There
Estes Park, CO