Cheesman Canyon: Below Cheesman Dam

Cheesman Canyon — Fishing Report for Monday, April 27, 2026

Quick Stats

Flow: 135 CFS | Trend: Stable | Fishability: Prime | Weather: Chance rain showers and thunderstorms, high 59°F

The Bite

If there's one day this spring to make the hike down Gill Trail, today has the ingredients. Overcast skies, temperatures in the upper 50s, and scattered showers are exactly the atmospheric conditions that trigger dense BWO activity on Cheesman — and April is peak month for it. Expect the hatch to build somewhere between noon and 2 PM and potentially run through late afternoon. When it fires, fish should be rising in pods through the slower tailouts and along the softer edges of mid-river seams. Pick your fish, read the rhythm, and commit to a single riser rather than casting into the crowd.

Flows at 135 CFS are sitting comfortably in the ideal band, and with snowpack running well below normal across the basin this year, the usual late-April runoff anxiety is largely off the table. Don't expect a sudden blow-out — this gauge has been flat for days. Water temps aren't available from this gauge, but seasonal patterns suggest somewhere in the mid-to-upper 40s°F, which puts fish in an active feeding mode without the lethargy of cold early spring.

One honest caveat: the afternoon thunderstorm window is real today. Lightning in a granite canyon is not a situation to push. Keep an eye on the sky after 2 PM and be ready to get off the water if storms build. Morning nymphing before the hatch is a productive fallback, and scuds and midges will keep fish interested until the BWOs arrive.

What to Fish

• Sparkle Dun BWO #20 — Point dry during the hatch; let it ride the film drag-free through rising fish
• Barr's Vis-A-Dun #20 — Excellent alternative when fish are keying on flush-floating duns
• RS2 Emerger #20-22 — Trail 12–18" below a Parachute BWO when fish are sipping subsurface; this is the pattern when refusals stack up on duns
• Pheasant Tail #18-20 — Anchor nymph for morning rigs before the hatch develops
• Scud (orange/pink) #16 — Dead weight near weed beds; effective all day as a point fly
• San Juan Worm (red) #14 — Reliable producer on the bottom, especially in deeper slots

Tactics & Rigging

For the hatch window, rig a single dry on 12–14 feet of leader tapered to 6X fluorocarbon — Cheesman fish are notoriously leader-shy in clear water. If you're seeing refusals on the dun, drop to 7X and switch to an RS2 emerger fished in the film. A dry-dropper setup works well before the hatch: try a Parachute BWO as the indicator with an RS2 or Pheasant Tail dropped 16" below on 6X. Keep the dropper light enough that the dry can still float naturally.

For morning nymphing, run a Pheasant Tail or Scud on point with a San Juan Worm trailing 12" behind, weighted with a single small split shot above the top fly. Fish the deeper slots and the transition zones where fast water dumps into slower pools — that's where fish hold before the hatch pulls them up.

Access & Logistics

The 1.5-mile hike down Gill Trail is the only way in — plan 30–40 minutes each direction and wear layers. The trail can be slick after rain, so traction matters today. Arrive by 10 AM to scout your water and claim a position before the hatch. Crowds are typical for April on Cheesman — give other anglers at least 100 yards of space and don't crowd a pod someone is already working. Clean, drain, and dry all gear before and after — New Zealand mudsnails have been documented in the South Platte drainage. Verify current regulations with CPW before fishing; this is Gold Medal catch-and-release water with artificial flies and lures only.

Stop by Flies & Lies or Trouts Fly Fishing for current fly selection and local intel before heading out.

Looking Ahead

Rain and storm chances persist through Wednesday before a brief clearing — the overcast pattern is actually favorable for BWO activity, so Tuesday and Wednesday could fish similarly well if lightning stays manageable. With a very light snow year in the basin, expect flows to remain stable or drift slightly lower through early May, extending what's shaping up to be an unusually long prime window on Cheesman.