Fly fishing report · West

Big Thompson

A practical Big Thompson plan built around Rocky Mountain National Park rules, Big Thompson Canyon access, RiverReports flow support, and trout-friendly seasonal timing.

Check flow & weather

Today's fishing decisionMost live data available

Use caution

Big Thompson is a cautious call right now.

The NWS forecast is near 84F. Fish early and verify water temperature where trout stress is possible.

Best supported approachBank / edge

Watch nextHeat: The NWS forecast is near 84F. Fish early and verify water temperature where trout stress is possible.

Updated Aug 3, 1:03 AM UTCUsually refreshes about every 45 minutes

Best supported approachBank / edge

Compare wading, bank fishing, and floating before choosing how you will fish.

WadeNot advised

Wading is the most sensitive plan today. Use protected edges only, avoid crossings, and downgrade quickly if clarity or current feels wrong.

Bank / edge · Best fit56/100

Bank and edge fishing is the safer default when water is high, pushy, or not fully verified.

FloatNeed data

This report does not describe this as a primary mode. Verify legal access, depth, launches, and retreat options before planning around it.

Check before you drive

Current flow and weather.

Look at whether the river is rising or falling, then check wind, rain, and storms. These can change both safety and fishing.

Before you rely on this report

How current is this report?

Conditions can change quickly. Check these dates before you decide to fish, and open the official source when safety or rules matter.

River conditions: Checked Aug 2, 2026, 9:03 PM
Fishing guidance: Reviewed May 31, 2026
Public access: No reviewed map pin available
Rules and closures: Official rule links checked

View report sources See how reports are verified Report an error

Plan your access

Know where you can enter.

These are public parking, launch, trail, or recreation areas—not secret fishing spots. We never show an angler's private pins, notes, or photos here.

0: Shown on map
3: No map pin

Location checkedDescription only

Area description

Moraine Park

No map pin

Classic Rocky Mountain National Park meadow water; check current park access and reach-specific fishing rules first.

Restrictions and seasonal notes

US 34 provides the basic canyon corridor, but do not assume every turnout is a comfortable or legal fishing stop.

Inside Rocky Mountain National Park, a Colorado fishing license is required for anglers 16 and older and park-specific gear restrictions still apply.

Official source Checked May 31, 2026

Parking

Lake Estes to Waltonia corridor

No map pin

Special-regulation canyon stretch with many short stops, but parking and shoulder safety decide which pullouts are worth fishing.

Restrictions and seasonal notes

US 34 provides the basic canyon corridor, but do not assume every turnout is a comfortable or legal fishing stop.

Inside Rocky Mountain National Park, a Colorado fishing license is required for anglers 16 and older and park-specific gear restrictions still apply.

Official source Checked May 31, 2026

Area description

Lower canyon near Loveland

No map pin

Best used as a short-session option when the upper river is too crowded or still dropping.

Restrictions and seasonal notes

US 34 provides the basic canyon corridor, but do not assume every turnout is a comfortable or legal fishing stop.

Inside Rocky Mountain National Park, a Colorado fishing license is required for anglers 16 and older and park-specific gear restrictions still apply.

Official source Checked May 31, 2026

How to fish it

Treat this as a reach-by-reach canyon trout day.

The Big Thompson fishes best when you match your reach to runoff, canyon safety, and the current Rocky Mountain National Park or Colorado special-regulation section you actually plan to fish.

Use RiverReports for quick flow shape, then use USGS 06741510 as the official downstream flow check before committing to the canyon.
Inside Rocky Mountain National Park, special rules apply and several upper reaches are catch-and-release or closed; check the park page before you rig.
From Lake Estes downstream to Waltonia, Colorado lists artificial flies and lures only with immediate trout release, so rig barbless and keep handling short.
Skip the day during muddy runoff pulses, thunderstorm spikes, or if canyon pullouts and crossings force rushed wading decisions.

Why the score looks this way

HeatUse caution

The NWS forecast is near 84F. Fish early and verify water temperature where trout stress is possible.

Public alertUse caution

An Air Quality Alert is active near this forecast point, so the score is capped at caution until smoke and access conditions are checked. NWS alert: Air Quality Alert issued August 2 at 4:10PM MDT by NWS Denver CO.

Best mode nowUse caution

Bank / edge: Bank and edge fishing is the safer default when water is high, pushy, or not fully verified.

FlowHelps score

USGS shows 68 cfs with a stable over about 6 hours trend. Today's flow is within the normal seasonal range of 51 cfs to 88 cfs. Weather, water temperature, and access are the next checks.

SeasonHelps score

Summer: Primary dry-dropper season, especially mornings in the canyon and park meadow water.

Read the water

What changes the plan.

Stable summer and early fall flows usually offer the cleanest all-day trout fishing. During runoff, target softer seams and shorter sessions, and when the canyon is rising fast, choose another Front Range option.

Low clear water

Fish early and late with smaller dries, light nymphs, and longer leaders.

Moderate stable flow

Best all-around pocket-water condition for dry-dropper coverage.

Runoff or storm color

Stay near soft banks and eddies, fish bigger nymphs or streamers, or wait for the drop.

Warm afternoons

Lower canyon water can warm quickly; carry a thermometer and end the trout plan if temperatures climb.

Your trip plan

Know when to go—and when to skip it.

Best flows

Stable or dropping freestone flows with enough visibility to fish pockets and banks safely.

When to skip

Skip during muddy runoff spikes, lightning-heavy afternoons, or when lower canyon water is warm enough to stress trout.

Local plan

Base in Estes Park, check park rules and the lower gauge, then choose one upper reach and one canyon backup instead of trying to cover the entire river.

Backup water

Shift to Boulder Creek, Clear Creek, or a South Platte option if runoff or canyon safety does not line up.

Hatches & flies

Bring a flexible box.

TimingWhat to watchUseful flies

SpringMidges, BWOs, small stones, and caddisZebra midge, pheasant tail, BWO emerger, black stone nymph

Fly pattern · report suggests “Zebra midge”Zebra MidgeLook for a very slim tapered thread body, evenly spaced contrasting wire rib, a small bead, and no tail or wing. The reviewed classic is black with silver wire and a silver bead. Red, olive, brown, glass-bead, jig-hook, resin-coated, or tailed forms must remain labeled variations rather than replacing the classic identity.See photos & how to fish it

Fly pattern · report suggests “pheasant tail”Pheasant Tail NymphThe pilot page distinguishes the sparse original idea from the bulkier American form. Both use pheasant-tail fibers and copper wire, but bead heads, peacock-herl thoraxes, legs, flashbacks, jig hooks, and soft-hackle collars are variations that must be labeled.See photos & how to fish it + 2 more reviewed guides in the Fly Box

SummerPMDs, yellow sallies, caddis, ants, and beetlesElk hair caddis, PMD cripple, yellow stimulator, foam ant

Fly pattern · report suggests “Elk hair caddis”Elk Hair CaddisLook for a tented elk- or deer-hair wing, clipped hair head, dubbed body, rib, and hackle palmered along the body. The body color should be labeled because tiers often match different natural caddis colors.See photos & how to fish it

Fly family · report suggests “PMD cripple”Pale Morning Dun PatternsPMD names an insect group, not one fly. Pale nymphs, trailing-shuck emergers, upright or low-riding duns, cripples, and spent-wing spinners stay visibly separate.See family guide + 2 more reviewed guides in the Fly Box

Late summerTerrestrials and evening caddisHopper-dropper, beetle, ant, soft hackle caddis

Fly family · report suggests “beetle”Beetle PatternsBeetle flies range from simple foam shells to hair-bodied and sunken forms. A rounded back and compact profile distinguish the family from ants and hoppers.See family guide

Fly family · report suggests “ant”Ant PatternsAnt patterns can be foam, fur-bodied, winged, or sunken. The narrow waist and paired body lobes matter more than one material recipe.See family guide + 1 more reviewed guide in the Fly Box

FallBWOs, midges, and streamer windowsRS2, midge larva, olive bugger, small sculpin

Fly pattern · report suggests “RS2”RS2Start with the beadless architecture: two dark-dun Microfibett tails separated behind a slim, tightly twisted and visibly segmented dubbed abdomen; a fuller thorax; and saddle-hackle web clipped into a short angled wing bud. Rim Chung's original-style form uses natural beaver dubbing and hackle web. CDC- or Antron-wing ties, beads, curved hooks, flash, and tailless Avatar-style flies must remain labeled variations.See photos & how to fish it

Fly family · report suggests “midge larva”Midge Patterns by StageMidge wording can mean a threadlike larva, wing-padded pupa, film emerger, tiny adult, or visible cluster. Those profiles fish at different depths.See family guide + 2 more reviewed guides in the Fly Box

Start with short, high-percentage pockets before you cast to long obvious runs.

In Moraine Park and other flatter upper reaches, make the first cast count and avoid lining fish in clear water.

When the flow is pushy, fish softer banks, inside seams, and depth changes instead of trying to reach the heavy middle current.

Move often. The Big Thompson rewards a steady string of short productive stops more than one long stationary session.

Rules & closures

Check the official rules before you go.

Open the agency page to confirm the exact river section, species, season, tackle rules, limits, and emergency closures.

Official links checked

Rules for this river or sectionNo special rule found

We did not find a special rule for this river.

We checked the state source but did not find a clearly supported exception for this river. Check the official rules for the exact section you plan to fish.

Rules checkedJul 30, 2026

Report a correction ↗

Always follow the official rule

This summary helps with trip planning. The linked agency rule is the one you must follow.

Updates from anglers

What anglers are seeing.

Recent observations from general areas of Big Thompson. We review every update before it appears and never publish exact fishing spots, private access details, or photo locations.

Share what you saw Open in BSF

Angler updates are not loading right now.

You can still use the river plan above. Check back later for recent observations from other anglers.

Where this report comes from

Open the sources we checked.

Fishing guidance checked: May 31, 2026

Site check: Jul 14, 2026. We regularly test report links, live scores, flow and weather data, and page loading. The content date changes only when the fishing guidance or its sources change.

flowRiverReports: Big Thompson flowUSGS Big Thompson River at Loveland safetyNWS forecast point near Big Thompson regulationRocky Mountain National Park fishing rules accessRocky Mountain National Park directions and US 34 access regulationColorado special fishing regulations safetyColorado Parks and Wildlife water safety

Common questions

Before you leave.

Is the Big Thompson a wade river or a float river?+

This page is primarily a wade plan. Most anglers do best by fishing short public sections rather than trying to float the canyon.

Which flow source should I trust first?+

Use RiverReports for quick trend reading and USGS 06741510 for official context, then adjust for the specific reach because upper park water can look different from the lower canyon.

What is the most important regulation check?+

Check both Rocky Mountain National Park fishing rules and Colorado's special-regulation page if your day crosses the park boundary or the Lake Estes to Waltonia stretch.