Open 9 a.m. to 6 p.m. daily

Report Date: 10/9/2026

Conditions:

The South Platte below Cheesman Dam is maintaining a low, steady flow around 97 CFS, creating glass-like clarity throughout the gorge. Water temperatures are comfortably hovering in the mid-40s to low-50s range. Because the volume is constrained and the water is transparent, the trout are particularly skittish, taking shelter in slow granite drop-offs, deep waist-deep slots, and gentle foam seams. Staying far back from the ledge and minimizing movement on the bank are critical to keeping fish in position.

Weather:

Short-term

Current autumn conditions bring dramatic daily temperature swings through the canyon floor. Crisp, near-freezing dawn starts quickly give way to mild, sunny afternoons in the upper 50s and mid-60s. Thermals and light mountain gusts routinely kick up past midday, dislodging late-fall leaves and knocking remaining land insects off the shoreline vegetation into the current.

Long-term

Looking deeper into fall, shorter daylight windows and periodic cold fronts will steadily draw down surface water temperatures into the lower 40s. As the chill takes hold, resident trout will abandon swift summer riffles and migrate toward the deepest, slowest winter holding pools. Expect these low tailwater releases to remain stable, making stealthy approaches and fine-gauge rigging the primary recipe for success over the coming weeks.

Hatches:

Tiny midges account for the vast majority of daily feeding, with steady hatches popping throughout the cold mornings. Blue-Winged Olives (BWOs) offer the most reliable afternoon emergence, especially when cloud cover or light overcast conditions move over the canyon. On warmer, sunny stretches, trout will still rise opportunistically to small terrestrial offerings like foam ants, beetles, and late-season hoppers drifted tight to the rock walls.

Tactics:

Technical finesse is paramount under these low-flow conditions. A long 9 to 12-foot leader ending in 5X or 6X fluorocarbon is essential to prevent lining fish in the clear water. A two-fly nymph rig set up for sight-fishing works exceptionally well—anchor the setup with an understated attractor like a small scud, wire worm, or caddis larva, then drop a size #22-24 micro-midge or Baetis emerger behind it. During afternoon hatches, switching to a delicate dry-dropper or a single dry fly fished along quiet seam lines will produce consistent surface strikes.

Tips:

This is an area where we offer guided fly fishing trips. We are one of two outfitters permitted to operate in Cheesman. There is no better way to learn an area like Cheesman Canyon than hiring one of our Orvis-endorsed professional guides!