In this report
107 CFS and holding — autumn midge season is here, and this tailwater is fishing clean
We’re sitting at 107 CFS this week on the Pueblo tailwater — right in that stable, fishable band where this dam-controlled water shines in October. Water temp is holding at 60°F, which means the trout are alert and feeding predictably without the thermal stress that hammers summer low-flow days. Before you drive down, check the flow chart on this page; reservoir releases can swing hard day to day, and what reads good this morning might be different by evening. But the current number is workable, and the temperature tells you the fish are thinking clearly.
At 107, you’re not wading in a creek, but you’re not muscling through waist-deep current either. The channel is defined, and the trout are holding tight to structure — deep slots, current seams behind the larger rocks, and the slower inside bends where they can hold without working as hard. This is not a condition that demands heroic casts or sprawling coverage; it rewards precision and patience, which is exactly how October midge fishing works on this water anyway.
Midges run the show; BWO is the secondary play
October on a Colorado tailwater means two things: falling water temps that cool the reservoir, and a hatch calendar that’s turned solidly toward small dries and emergers. The midge is the workhorse here — and it always is on the Pueblo tailwater. Black Beauty, Mercury Midge, and zebra midge patterns in #20–24 will be your confidence flies, especially in low-light and overcast windows. Emerger imitations (RS2 in black or olive, #20–24) will actually outfish the dries most days because the trout see more emergers than adults.
BWO (baetis) will start showing on gray days, particularly if we get morning cloud cover. Tie in #20–22 — not bigger — and keep them sparse. The tailwater’s gin-clear water at this flow means the fish see everything. A #18 or #16 BWO will look cartoonishly oversized to a trout that’s been eating #22 emergers all morning.
The browns are also starting to think about pre-spawn behavior. You’ll see more aggressive takes in the deeper, cooler holding water — especially at the tail end of the day. If you want to test that, a #6–8 streamer (black, brown, or olive Woolly Bugger or similar) fished slow and tight to the deepest banks can draw strikes that feel entirely different from the midging game.
Rig tight, fish deep, stay delicate
At 107 CFS and 60°F, the water is clear enough that a clumsy presentation will put down fish. You need tippet in the 6X–7X range (I’m running 6X most days, 7X when light is bright or if I’m fishing the shallower inside bends). It feels thin, but it turns over better and lands softer than heavier stuff on this water, and the trout respond.
The money rig this week is a heavy anchor fly — a Barr’s Tungsten Midge, Zebra Midge, or Mercury Midge in #22–24 — with a slightly lighter emerger (RS2, BWO emerger, or soft Midge Emerger in #20–22) suspended 12–18 inches above it on a short dropper. Weight that anchor to tick bottom in the deeper seams and along the far bank where the current carves. Add split shot 2–3 feet up the leader if you need to reach the bottom fast, but be surgical about it — one #1 or #2 shot is often enough at this flow.
Fish this rig on an indicator or tight-line, depending on your preference. A small yarn indicator 2–3 feet up the line gives you visual feedback and keeps your flies in the zone longer on each cast. Tight-line nymphing works equally well and is less visible in the clearest tailwater stretches; set on feel and slight motion changes.
The deep slots along the outer bends are where the trout are living. The thin water over the sun-exposed gravel? Skip it unless you’re matching a specific adult rise. Your casting distance should be deliberate — 30 to 40 feet is plenty. Let the fly dead-drift, follow it with your rod tip, and mend only when drag is obvious. The fish aren’t moving far at this flow to chase anything.
Access and fish welfare: dawn and dusk matter now
The Pueblo tailwater’s Gold Medal designation and year-round fishery mean you can be out here in October with genuine hope. The milder weather and stable winter-like flows make this tailwater special — it doesn’t crash into the thermally brutal doldrums that plague summer low-flow days. That said, 60°F is cool but not cold; the trout are feeding actively, and the tailwater’s proximity to the city means access is straightforward and foot traffic is manageable this time of year.
Verify current special regulations on the upper sections closest to the dam before you fish — catch-and-release and artificial-only rules tighten on the most restrictive stretches, and the exact sub-section boundaries and bag limits change year to year. The tailwater is worth knowing in detail; it fishes completely different from the freestone Arkansas you might know upstream.
Fish early or late this week if you can. The low light windows — first two hours after sunrise, the hour before and after sunset — concentrate the midge emerger action and will give you more takes than midday dead-zone fishing. The water is clear enough that midge action happens all day, but the predatory window is dawn and dusk.
This is autumn on a tailwater that knows how to do autumn. Get tight to the bank, fish small and patient, and let the current do the work.