In this report
252 CFS and a Window That Won’t Last
The gauge is reading 252 CFS—dead center in Deckers’ sweet band, and for once that’s not hyperbole. You’re looking at wading that doesn’t demand a second mortgage on your ankles, holding water that still has enough push to keep fish from locking down in the shade, and visibility clean enough to read the riverbed without squinting. This is the week to move around, cover water, and fish with intention rather than prayer. The thing is, midsummer on the South Platte means water temps are creeping up, and stable, moderate flow like this can evaporate fast when afternoon heat builds. If you’re thinking about driving up to Deckers, don’t overthink the timing—this current window is the one to use.
The Trico and PMD Show, with Caddis on Standby
By early July, the Trico spinner fall is your alarm clock. These tiny mayflies (#20–24) show up in the morning hours—usually between first light and mid-morning—and the fish key on the spent spinners drifting flush in the film. It’s not a long window, and it demands small, sparse imitations and patience, but if you’re at the water by 6:00 a.m., you can catch honest trout on Trico spinners before the hatch closes and the day turns over to other food sources.
Once the morning fade ends, shift your attention to PMD nymphs and emergers. These mayflies (#16–18) are still producing throughout midsummer on this reach, and they’re less time-specific than the Tricos—you can fish them all morning and into the afternoon without watching the clock. The emerger is the key pattern here: a #18 PMD emerger fished in the film or just subsurface will outfish a dry when fish are feeding on the transition, which is most of the time right now.
By evening, caddis activity picks up. Nothing dramatic—not a blanket hatch—but enough to matter. Evening caddis (#14–16) bouncing along the fast-water seams and the gentler runs near the banks will draw rises when the water cools slightly after sunset. Fish a size #15 or #16 ELF or Elk Hair Caddis in those last couple of hours before dark, targeting the current tongues and the softer edges of the faster runs.
Midges remain the year-round staple here. A #22 Black Beauty or Mercury Midge fished deep on a dropper, or an RS2 emerger in the film, will catch fish any time of day. Don’t ignore them just because the PMDs and caddis are active—nine out of ten fish feeding subsurface on Deckers are likely eating midges, not the bigger stuff.
How to Rig for 252 CFS
At this flow, you want to fish two systems: a nymph rig for deeper slots and current breaks, and a dry-dropper or emerger-only setup for the shallower, faster water.
Deep-water nymph rig: Use a heavier Barr’s Master Bug or Beadhead Pheasant Tail (#18–20) as your anchor, tied to 4X tippet. Two to four feet above it, add a #18 PMD emerger or #22 Midge on 5X. Add a single split shot about 10 inches above the point fly—not a heavy wrap, just enough to reach the bottom and stay there for 3–4 seconds of drift. An indicator is worth using here; the water is clear enough to see it, and Deckers’ fast riffles will tell you instantly when you’re hung or when a fish takes. Fish these rigs in the deeper slots, the inside bends where the current stacks, and the runs immediately downstream of the fast water.
Dry-dropper for faster, shallower sections: Start with a #16 or #14 Chubby Stimulator or a Caddis Dry as your indicator fly (yes, it floats and fishes), and suspend a #18 PMD emerger or #20 Midge on 5X about 18–24 inches below. Cast across and slightly upstream, mend to keep the line tight, and watch for two things: a take on the dry (rarer but honest) or a twitch in the line that says the dropper has gone under. This setup works beautifully on Deckers’ open, roomy runs where you have room to move and recast without snagging willows every other throw.
Tippet: Use 5X for the small emergers and midges, 4X for the heavier nymphs and larger dries. Deckers’ water is clear, but the fish aren’t as selective as Dream Stream or the canyon upstream—they’ll eat a slightly heavier tippet if the fly is right.
The Water Types That Matter This Week
Skip the tiny pocket water and focus on three zones: the fast, broken riffles in the upper ends of your access points (near Deckers Bridge and Trumbull), the deeper runs with steady current in the mid-sections, and the softer current along the banks where terrestrials and caddis collect as the day warms.
The riffles are the easy sell—they always hold fish, and at 252 CFS they’re not blown out. Work them methodically with your nymph rig, adding extra split shot if you’re not ticking bottom every third or fourth drift.
The deeper runs, the ones where you can see the riverbed but the water is still over your knees, are where the bigger fish live on a week like this. These slots have enough current to feel alive but enough depth that a fish doesn’t have to bolt the second the light changes. Fish them tight, with an indicator, and expect the take to come as a subtle twitch, not a violent yank.
The softer bank water and the current seams near the vegetation shine in the afternoon and evening. This is where caddis and terrestrials (ants and beetles) are most effective. A #12 or #14 black ant or beetle fished on a short leader in the film, or a #16 Caddis dry on a dry-dropper, will catch honest fish when the main current runs feel slow.
A Note on Temperature and Timing
Early July means water temps are already in the mid-60s. This flow will keep them reasonable, but be aware: if you’re going to fish, go early and fish hard through mid-morning, then reassess after 2:00 p.m. The afternoon sun heats the water faster than the ambient air, especially on Deckers’ open banks with little shade. If the fish go quiet after early afternoon, they’re likely uncomfortable, not disinterested. Don’t grind on them in the heat of the day—fish the morning window, take a break, and come back for the evening caddis when the sun angle drops.
CO-67 is busy on weekends in July; a weekday trip will give you more room to work and easier parking. Verify current regulations before you go—the 2 trout over 16 inches rule holds for this reach, but always confirm year to year.