Trouts Journal

Trouts Warmwater Fly Fishing Forecast | September 2021 Edition

Ivan Orsic / Sep 2, 2021

What an August! Plenty of rain and warm weather kept all the Front Range in prime shape. Summer is normalizing a bit, and while September can be the most technical month in the warmwater world, with a few specialized tactics, it can be just as good.

The Denver South Platte

The Denver South Platte has reached classic form; low, clear and a tactical sight fishers paradise. Even though it will be much more persnickety in the coming months, the high flows of the past few weeks have greatly reduced pressure, and the Carp and Smallmouth are a little less wary than they would be during a normal Summer. With the dramatic increase in clarity, you will be able to SEE almost every fish in the river, and that really helps the odds, as you have lots of targets. But, Carp and DSP Smallmouth are smarter than most, and the stealth approach and presentation are CRITICAL. Two big things you can do to decrease unwanted blow-ing of shots;

1.) Wear Camo.

Carp can see in 'true color', and can easily discern something out of place, particularly when the object is moving. Camo is a proven tool by the DSP’s most prolific anglers to blend in and reduce spooking. The Simms Riparian Camo Solarflex Line is excellent for getting lost in the flora of the high banks, and the Cloud Camo line can make a big difference when above the bank. I am waiting for a color-changing option, so I can blend in on both scenarios on the same day... Where are we at on this Simms Design Team?

2.) Reduce your false casts.

In the many Carp Schools, and guided trips Barry Reynolds and I have done over the years, the biggest culprit of spooked fish outside of them outright seeing you, is; Too many false casts. The repeated arm motion and line carried in the air over a tailing fish can immediately trigger a fish to stop feeding and flee. Practice is the solution. If you can carry 20-30ft in the air, and shoot up to 50ft on one haul, you WILL maximize the presentation, and get your fly in front of the fish when it is the most fired up about feeding. As a bonus, you will be well suited to make your captain happy on your next Saltwater Adventure!


Night Time is the right time. With heavy foot traffic and hot ambient temps during the day in our local parks and open spaces, Bass and other warmwater targets are playing it safe and sticking close to deeper structures, where food is abundant in the Summer Heat. With absence of visible overhead predators and a nice cool down, they will patrol the shallows under the cover of Darkness looking for a meal. Bass especially, are also much more apt to eat off the surface at night, making topwater a prime tactic. Scurrying mice and popping frogs are all prime protein opportunities after the lights are out. While there are lots of conflicting opinions on the subject, my best topwater nights have been on a Full Moon or New Moon (Peak Lunar events) and before moonrise or after moonset. The window seems to be bigger on New Moons, but contrary to what you would think, the brightness of a Full Moon seems to slow down the action. As for subsurface flies, consider contrast against any ambient light from above. You can fish any color you want, as long as it is black…


September into October in Larger Water is all about finding bait. Fish will be highly pelagic, even Carp, and will follow the bait to stay close to the protein. It is not uncommon to see Carp caught on baitfish this time of year, mixed in with the Bass and Walleye, as metabolism is high for all species, and they are willing to expend a bit more energy to eat. Bait Schools will remain deep as summer temps reign; See last month’s tips on Sinking Lines, but as the waters cool, they will move higher in the water column and in closer to shore. While relatively rare as compared to the states to the East, there are opportunities to fish Baitfish Blitzes in Colorado in the late summer and early fall. Just like striper blitzes, looking for birds and busting bait can be an epic way to catch Wiper, Smallmouth, Pike, and others. This can also be productive from a topwater standpoint when walk-the-dog style flies are employed. For Largemouth in late summer, you need to think like a conventional angler and employ finesse jigged presentations (as best as you can with a fly rod). Heavy jigged flies with lots of action, twitched around structure will produce quality Largemouth, fat with the bounty of a great summer!

Summer is the time to go explore Colorado outside of the usual mountain trout destinations. You won’t have to fight I-70, crowded campgrounds, or Subaru choked trailhead parking. Eastern and Southern Colorado have infinite warmwater opportunities, and you may be the only one there with a fly rod in hand….


Umpqua Barry's Carp Fly

For those times Carp are particularly...well, picky

Umpqua Meat Whistle

Nighttime subsurface bass option

Rainy's Cheeky Mouse

For those nighttime topwater moments.

Umpqua Crease Fly

A must-have fly for any saltwater trip, and a good addition for targeting predatory freshwater species as well.

Rainy's Boobie Fly

For those eager and aggressive Panfish

Capt. Ray's

This particular fly has a sparse profile and thinner shape, making it great for a multitude of fishing situations.

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