Upper Colorado River — 9/16/25 Fishing Report With CRO guide Matt Weldon

flyfish19
Sep 16
3 min read

Matt Weldon is a veteran Colorado Fly Fishing guide who is guiding nearly every day for Colorado River Outfitters.

Fall has been off to an excellent start on the upper Colorado — hungry trout, crisp mornings, and some classic seasonal windows. Below is what Matt’s been seeing on the water lately and the exact tactics and flies that are putting fish in the net.

Quick snapshot

Morning: midges and a few tricos showing.
Midday: small baetis activity — perfect for a hopper-dropper approach.
Afternoon: fish move up onto dries — X-Caddis and Purple Ms. Tickle Cripple are producing lots of looks.
Bonus: on low light/cloudy days streamers tight to the bank and through fast water are getting aggressive strikes.

Tricos are a small black mayfly with a long tri-tail.

Morning — midges & tricos

Start early and slow. Fish are keyed on tiny midges and the occasional trico—long, delicate presentations are the ticket.

Tactics & setup

Flies: Daysaver midge, cream, size 22, Renegade size 20
Presentation: very long, drag free drifts — keep everything light (thin tippet, long leader) and minimize drag.
Focus: seams, soft tails, and slow water near riffle edges where midges collect.

Hatch note: mornings are your best time for tiny dries and ultra-fine presentation. Watch for faint sipping or little rings — those subtle takes are real.

Midday — hopper + baetis (hopper-dropper)

As the sun climbs, small baetis come on and fish will often key on a two-fly approach.

Tactics & setup

Rig: hopper-dropper (float a Trigger belly hopper with a dropper team).
Flies: Trigger Belly Hopper – size 8 (top), orange perdigon – size 16 (dropper), Sexi top bwo – size 22 (micro dropper).
Water to fish: drop-offs, seams below riffles, and the edges of faster water where baetis trickle downstream.
Presentation: cast upstream across the seam, mend to get a drag-free swing through the seam and drop-off. Keep the hopper lively but natural — give short, erratic twitches to sell it.

Hatch note: small baetis will pull trout off the bottom into those seams — the hopper attracts attention, the perdigon and Sexi top pick up the picky feeders.

Afternoon — dries come alive

Later in the day fish are often looking up. Time to switch to dries and enjoy the visual game.

Tactics & setup

Flies: size 18 X-Caddis to a size 18 Purple Ms. Tickle Cripple.
Technique: Dead drift through the fast riffles and drop offs. Work foam eddies and foam lines on the flats. Make short, precise casts into pockets and seams and let the fly sit where a natural would be.
Presentation: short drifts, watch the flies closely, and be ready for a subtle sip.

Hatch note: afternoons can produce selective trout — smaller, realistic profiles and perfect drifts win the day.

The Ms. Tickle Cripple is a great all around dry fly that imitates many different emerging insects. Matt’s favorite is purple, size 18.

Bonus tactic — streamer days (cloudy / low light)

When the clouds roll in or the light drops, switch gears.

Tactics & setup

Strip streamers tight to the bank and through fast water and current seams.
Fly: articulated Thin Mint (works very well some days).
Retrieve: short, aggressive strips through seams and cutbanks; on edges try heavier, quicker pulses to trigger reaction strikes.

Pro tips from Matt — observation & thoroughness win

Matt preaches two things above all: be thorough and watch everything. Here are his go-to reminders:

Fish every seam twice. If a spot looks prime, don’t leave after one pass — change depth, slow down, or try a different fly before moving on.
Read the bug activity. Often the river will tell you what’s going on and what the trout might be keyed on. Look for insects emerging close to the surface, flying around or crawling on your waders/boat.
Micro-adjust constantly. If you’re not getting looks, shorten/lengthen your dropper, change tippet, swap the perdigon for a slightly heavier or lighter fly. Small changes matter.
Be patient with drifts. Try not to over cast, let your flies work a run and don’t get too anxious to recast.
Scan before you cast. Walk a beat, look for foam lines, bubbles, insect activity, and recent casts by other anglers — these visual cues direct you to where trout will be.
Keep a clean presentation. Make sure to check flies regularly for debris or moss.

Want to fish with us?

This fall is shaping up to be a fantastic one on the upper Colorado. Book a float trip with Matt Weldon or any of our expert CRO guides and let us put you on the water where the fish are feeding and the scenery can’t be beat.

Here’s a few photos from trips in the last week: