Autumn Angling in Colorado


As long summer days change slowly into dark cold nights, trout prepare for winter. Brook and Brown trout dress up in spawning colors and Rainbows follow the migration. The change in seasons brings a change in fly fishing tactics as well. Adjusting your tactics will allow you to continue catching trout on the surface and under the water right up until the edge of winter.

Water Temperatures

Daytime temperatures play a big role in a trout’s willingness to feed on the surface in the autumn. If summertime temperatures persist into the Fall, sun up to mid-morning and again in the evening become prime times for targeting trout. Should the Fall temperatures come early with daytime temps in the 50s the window anglers will want to fish will be from mid-day through the afternoon.


Brown trout actively hunt for terrestrials coming into fall seeking, grasshoppers, beetles and winged ants. Ants are a requisite in any autumn fly box. As fall swings into progression ants play a major role along stream banks for dry fly anglers. Ants develop wings and seem to be found struggling on waterways throughout the Rocky Mountains tempting hungry trout along the way. Prospecting along the riverbanks with winged ant patterns and grasshoppers can be an exhilarating affair. Trout don’t just sip a grasshopper they hit it to kill it. Large, kicking, struggling food sources are taken with a little more vigor than a size 18 Mayfly. Trout do not like anything struggling in their gullet or grabbing ahold of their gills so the resultant strike is forceful. Stepping up in tippet weight class prevents inadvertent breakoffs from powerful hits.

Hatches of October caddis appearing throughout the fall. The spruce moth can also prevalent and both are often imitated by a large elk hair pattern. Blue Wing Olives show up in smaller sizes than their summer cousins. A size 18 Parachute Adams fools most finicky surface feeders and some anglers too. The Griffith’s Gnat is a proven winner for autumn afternoons as well. The best advice when fishing with tiny dry flies is to set on anything that eats on the surface even if you can’t visually track your fly. A size 16 Parachute Adams supports a light nymph, such as a small pheasant tail, when fished as the top fly in a BWO dry dropper combination.


Nymphing in the autumn is a productive approach with lower flows and a decrease in fishing pressure trout are very willing to take a sub-surface fly that is well presented. Selecting flies to coincide with the time of year and temperatures you are encountering is the code you need to break. Subsurface offerings include large stoneflies nymphs down to the diminutive midge larva flies. An RS-2 fished in tandem with another nymph is a good place to start. Once you have determined some productive fly choices anglers need to choose how and where to present their flies.Concentrating on mid-river current seams and bubble lines well off the bank focuses the nymphing angler’s intentions into the correct area.

Another subsurface offering that targets many trout in a river would be to use an egg pattern. Large brown trout moving into spawning areas in late fall have a contingent of rainbows following them awaiting the release of eggs. Whitefish and Brook trout are both fall spawners adding to the egg melee tumbling down the river. Choosing to fish an egg pattern is a debatable subject in fly fishing circles and a topic for another time, however, knowing eggs are present in a river leads anglers to match a prevalent food source trout are exploiting. Matching the hatch with the egg game is another puzzle to decipher with the size, color and texture (think Otter’s eggs) of your egg pattern becoming choices anglers need to work through.

Minimal Pressure

Pressure by anglers is on a downturn during autumn. Sportsmen must choose to divide their time between field and fish. School has returned to normal calling vacationing anglers back to work as well. Previously crowded waters become deserted stretches. The river has a quiet feel when preparing for a long winter.


The colder temperatures that are more prevalent in the Fall require a little more attention to maintain comfort. Wading boots, one size larger than normal accommodate thick socks in the cooling waters of autumn. Layers of fleece and primaloft build walls of warmth under waders. As the evening sky comes earlier each day, by employing some well thought out tactics, fly anglers can stretch their time on the water right up to snowfall. Chasing the autumn trout in Colorado during one of the most beautiful times of the year can be very rewarding. Adjusting to the changing conditions as we slide into winter insures success on the autumn water we all love. Try a guided fly fishing trip with Vail Valley Anglers to experience Colorado’s excellent Autumn Angling.

Mike Salomone