In this report
224 CFS: Below the Sweet Spot, Above the Wall
Current flow sits at 224 CFS—below the ideal 250–400 band for this water, and noticeably shy of the 265–305 range where Cheesman’s pocket water really spreads the fish out. What does that mean in your waders? Fish are compressed into the better-oxygenated slots and runs. Holding water shrinks. And educated trout—this canyon grows them—get nervous faster when they’re crowded into fewer lies.
The upside: you don’t need to wade into the granite boulders as aggressively as you would at 350-plus CFS. The current is manageable for foot-traffic on the Gill Trail. The downside is straightforward—this is ultra-technical, experienced-angler territory right now. Long leaders, tiny flies, and a reading that pushes you toward the small end of the spectrum are not negotiable. If you’re comfortable fishing #24 midges on 5X tippet and reading the micro-holding water in a low-flow canyon, you’ll find fish. If you’re expecting to swing ugly buggers through chest-deep runs, go south to Deckers this week.
Water temperature is the real concern. At 224 CFS, volume is low enough that solar heating and the August sun are having their way with this tailwater. Temps are trending toward or into the low-to-mid 60s°F in the afternoon. These are wild, large, heavily-educated fish living in a narrow band of good holding water, and stress from warm water plus crowding is real. Plan your hike and fishing for early morning and dusk. Noon to 3 p.m. is scouting time, not fishing time—walk the canyon, observe where fish are holding as the sun peaks, but don’t hammer the water when it’s warmest.
Tricos and Midges: The Primary Morning Window
Trico spinner falls are the main event at Cheesman right now, and they’re happening early—6:30 to 8:30 a.m., before the sun clears the granite walls and the water warms. The flies are tiny: #20–24 black or dark-olive bodied spinners (Barr’s Spinner or similar) with clear or light-dun wings. The hatch itself is on the water by 6 a.m., and the spinners are falling by 7. This is not a 45-minute window—fish it hard while it lasts, because once the air warms, it’s over.
At 224 CFS, the Trico fall will be concentrated in the slower, deeper pockets where fish can pick off spinners without fighting current. You’re not looking for a wide band of rising fish; you’re looking for 2–3 dedicated feeders in a pocket the size of a bathtub. Get close (the canyon’s tight anyway), false-cast as little as possible, and drop a #22 Trico spinner on a 6X tippet with a 12-foot leader. One or two natural drifts. If the fish don’t take, move on. At this flow, every trout you spook gets remembered.
After 9 a.m., Tricos are done, and you slide into the morning midge game. Midges—small black Beauty or RS2 emergers in #22–24—hold the morning from 8 a.m. until the PMD pre-hatch stirs things up around 10. Fish them tight-line or under a small indicator, 12 inches off the bottom in the deepest slots. This is where the micro-weight game matters: a single small split shot or a tungsten bead on the point fly, and a #24 emerger on a 15-inch dropper. The whole rig has to drift through maybe 18 inches of water column; anything heavier and you’re snagging. Anything lighter and you’re not reaching the bottom where these fish are stacked.
PMDs and Caddis: The Afternoon Shift (If You’re Still There)
By 10 a.m., pale morning duns start pushing nymphs in the column. You’ll see a few dries by late morning, but at 224 CFS, the real action is sub-surface: #18 PMD emergers (olive or pale), fished the same way as the midges but with a slightly heavier anchor (a Barr’s Squirmy or small #18 pheasant tail) to get down faster as the water warms and fish move into the deeper slots. Expect the PMD hatch to peter out by 1 p.m.
Caddis—tan or olive #16–18 Elk Hair Caddis—will show in small numbers in the late afternoon, maybe 4 to 6 p.m., but at this flow and temperature, don’t bank on it as your primary dry-fly game. Fish it if you see it; don’t plan your day around it.
The Rig That Works Here This Week
Point fly (anchor): #18 Barr’s Squirmy or small pheasant tail, unweighted or with a small tungsten bead.
Dropper (18 inches back): #22–24 RS2 emerger or midge.
Split shot placement: One small split shot 8–10 inches above the dropper, or none if you’re using a bead-head anchor and water is shallow (under 18 inches).
Tippet: 5X to the first fly, 6X from the first fly to the dropper. The light stuff matters because the water is clear, fish are spooked, and at low flow, you have no margin for error.
Indicator vs. tight-line: At 224 CFS, tight-line nymphing is your friend. An indicator works fine, but the canyon’s pocket water is too short-drifted for a long-line dry-dropper setup. Mend aggressively and feel for the take.
Where to Focus Your Time
The deep slots between major boulders are the entire game this week. Fish the slower water—the places where current breaks and a trout can hold without working. At 224 CFS, these pockets are narrower and more obvious than they would be at 300-plus. You’re not spreading yourself across the whole canyon; you’re hunting 6 to 8 good lies per 100 yards of canyon.
Avoid the faster, shallower runs unless you see rising fish. The water is too warm and the margins too thin for fish to waste energy there.
A Word on the Hike and Heat
The Gill Trail is steep and rocky in sections, and August heat on exposed granite is real. Start before dawn if you’re targeting the Trico fall. Bring three times the water you think you need. If you’re hiking to prime morning water, you’ll be on the trail by 5:30 a.m.—the canyon mouth (roughly 1 mile in from the trailhead) is where most anglers fish, and you can reach it in 40 minutes if you know the way. Fish hard until 10 a.m., then consider dropping back out rather than baking in the canyon at midday. The fish won’t cooperate when temps peak, and you’ll be safer and fresher for a return trip when it cools.
This is not an easy week, but it’s the week we have. Low flow and heat mean precision and discipline. Work the early hatch, fish small, and respect the canyon’s narrow margins. That’s how Cheesman always fishes—this week, the river is just saying it louder.