Fishing Report: South Platte River at Cheesman Canyon

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Mid-September Fishing Report: Cheesman Canyon

Current River Conditions

Currently, Cheesman Canyon is flowing at a steady 290-400 cubic feet per second (cfs), rejuvenated by recent afternoon showers that have added a touch of excitement. The water remains crystal clear and refreshingly cold, holding a perfect temperature in the 50s—ideal conditions for keeping the trout active and ready to bite. However, don't be misled; these trout are incredibly discerning. If you're not cautious, they will spot you from a distance. Given the recent uptick in visitors, it's wise to arrive early to avoid the crowds and secure a prime fishing spot.

What's Bitting? 

The hatches in Cheesman Canyon have been a bit erratic lately, but there's still plenty of action for those willing to work for it. You'll see a mix of midges, Blue Wing Olives (BWOs), Pale Morning Duns (PMDs), caddisflies, Tricos, and the occasional stonefly. Here's what's been working best:

• Nymphs: With the water being so clear and the trout so selective, smaller nymph patterns have been the most consistent producers. Effective patterns include Foamback Emerger (#20-22), Rojo Midge (#20-22), Pat’s Rubber Legs (#10-16), Stalcup’s Baetis (#22), Barr’s PMD Emerger (#16-18), and RS2 (#20-22). Present these flies on a long, fine leader for a drag-free drift that tempts even the pickiest trout​

• Dry Flies: Dry flies can be deadly when the fish are looking up. Go small and precise with patterns like Mole Fly (#22), Parachute Adams (#20-24), Sparkle Dun PMD (#16-18), and Elk Hair Caddis (#14-18). Look for slower water and softer seams where fish might be sipping on emergers or taking dries off the top​

• Streamers: If you’re looking for bigger fish or want to mix things up, streamers can provide some explosive action. Woolly Buggers (#8-12), Baby Gonga (#6), and Mini Dungeon (#8) are solid choices. Cast these into deeper pools and along structures to provoke aggressive strikes from larger, territorial trout​. 

River Water Flow Chart

Hatches and Fly Patterns

Midges

• Patterns: Zebra Midge (Black, Olive, Red), Mercury Midge, Top Secret Midge
• Sizes: #20-24
• When to Use: Midges are a year-round staple on the South Platte, especially effective in the morning and late afternoon when fish feed on tiny insects just below the surface or in slower water.

Blue Wing Olives (BWOs)

• Patterns: Foam Wing Emerger, JuJu Baetis, Barr's Emerger BWO
• Sizes: #20-22
• When to Use: BWOs are a favorite during overcast days or in the late afternoon. The fish are often keyed in on these tiny mayflies, making them an excellent choice for dry fly fishing when you see surface activity.

Pale Morning Duns (PMDs)

• Patterns: PMD Emerger, Sparkle Dun PMD, Barr's PMD Emerger
• Sizes: #16-20
• When to Use: PMDs are more active in the mornings and early afternoons. Fishing PMD nymphs and emergers just below the surface or using dry flies when fish are visibly feeding on top can be very effective.

Caddisflies

• Patterns: Elk Hair Caddis, Buckskin Caddis, Goddard Caddis
• Sizes: #14-18
• When to Use: Caddis patterns are particularly useful during the warmer parts of the day and into the evening. Skating an Elk Hair Caddis across the surface can trigger aggressive strikes from hungry trout.

Terrestrials

• Patterns: Chubby Chernobyl, Fat Albert, Hopper Juan
• Sizes: #10-14
• When to Use: Terrestrial patterns such as hoppers, ants, and beetles are effective during the late summer and early fall months. Fish these along the banks and overhanging vegetation where trout often ambush terrestrials drifting in the water.

Attractor Nymphs

• Patterns: Pat’s Rubber Legs, San Juan Worm, Hare’s Ear Nymph
• Sizes: #10-16
• When to Use: Attractor nymphs are great for targeting deeper runs and faster water where trout are holding. These flies imitate various aquatic insects and are effective year-round, especially in higher water flows.

Emergers and Soft Hackles

• Patterns: RS2, Barr Emerger, Soft Hackle PT
• Sizes: #18-22
• When to Use: Emergers are highly effective when trout feed just below the surface during hatch periods. Soft hackles work well in riffles and seams where fish are feeding on emerging insects.

Streamers

• Patterns: Woolly Bugger, Mini Dungeon, Slump Buster
• Sizes: #6-10
• When to Use: Streamers are a great option for targeting larger, more aggressive trout, especially in deeper pools or undercut banks. For the best results, use them during lower-light conditions, like early morning or late evening.

Fishing Tactics

• Nymphing Techniques

  Nymphing is Cheesman Canyon's most reliable and productive method, where the trout are often found feeding subsurface. Given the river's depth variations and fast currents around boulders and seams, getting your flies down to the fish is crucial.

  • Two-Fly Nymph Rig: Use a two-fly nymph rig with a heavier attractor fly (like Pat’s Rubber Legs or a San Juan Worm) as your point fly, followed by a smaller, more natural nymph (such as an RS2, Zebra Midge, or Blue Wing Olive Emerger) as a dropper. This setup allows you to cover multiple water columns and imitate different food sources, increasing your strike chances.

  • Adjusting Depth and Weight: Constantly adjust the depth and weight of your nymph rig to match the changing conditions. Use enough split shot to get your flies down quickly in deeper runs and riffles. Pay attention to the speed of the current and ensure your flies drift naturally just above the riverbed, where fish are most likely feeding​

  • Strike Indicators: Use a strike indicator to detect subtle takes, which can be challenging to notice in the faster currents. Position your indicator at about 1.5 to 2 times the water depth you’re fishing to maintain the proper depth for your flies.

  Dry Fly Fishing

  Dry fly fishing can be highly effective during the right conditions, especially when there are active hatches.

  • Targeting Rising Fish: Look for rising trout in softer water, such as back eddies, seams, and slower pools. Present your dry flies with a delicate, drag-free drift. Patterns like the Parachute Adams, Sparkle Dun, and Mole Fly in sizes #18-24 can be effective, particularly during Blue Wing Olive (BWO) and Pale Morning Dun (PMD) hatches​(

  • Timing Your Casts: During hatches, trout can be very selective, focusing on specific stages of the insects. Match the hatch closely, and be prepared to change flies frequently if you see refusals. Timing your casts to coincide with natural drifts can help avoid spooking the fish.

  Dry-Dropper Rigs

  A dry-dropper rig is a versatile setup that allows you to cover both surface and subsurface feeding zones. This is particularly effective in Cheesman Canyon’s pocket water and faster runs.

  • Setup: Use a high-floating dry fly, such as a Chubby Chernobyl or a hopper pattern, and tie a small nymph or emerger (like an RS2 or Zebra Midge) as a dropper underneath. This combination allows you to fish both a dry fly and a nymph simultaneously, covering different depths and types of feeding behavior​

  • Presentation: Focus on casting into pocket water, seams, and near boulders where trout often hold and feed. A good presentation with a dry-dropper rig can tempt trout to strike either on the surface or just below it.

  Streamer Fishing

  While not as commonly used as nymphing or dry fly tactics, streamer fishing can produce aggressive strikes, especially from larger trout looking for a big meal.

  • Streamer Retrieval: Use streamers like Woolly Buggers, Slump Busters, or Mini Dungeons in sizes #6-10. Cast these flies into deeper pools, undercut banks, or along rock ledges, and retrieve them with a mix of short, erratic strips and longer pulls to mimic the movement of small baitfish or crayfish​

  • Timing and Conditions: Streamer fishing is particularly effective during low light conditions—early morning or late evening—or when there is cloud cover. It can also be productive when water clarity is slightly off-color due to rain or runoff, making the trout less cautious and more likely to chase larger prey.

  Reading the Water

  Understanding and reading the water is crucial in Cheesman Canyon, where the fish are often found in specific, predictable areas.

  • Focus on Productive Zones: Target areas where the current slows, such as behind large rocks, along seams, and in deeper pools. Trout use these areas to conserve energy while feeding on drifting insects.

  • Watch for Subtle Signs: Look for subtle clues like bubbles, surface disturbances, or slight changes in watercolor, which can indicate feeding fish or active seams.

  Adapting to Changing Conditions

  Conditions in Cheesman Canyon can change quickly, especially with afternoon rains that can increase flows and affect water clarity. Adaptability is key.

  • Stay Flexible: Be prepared to change tactics, flies, and locations based on the current conditions. If fish aren’t responding to one approach, switch it up. Try a different fly pattern, adjust your presentation, or move to a new spot in the canyon.

  • Early Start: Given the crowds and fishing pressure, especially on weekends, start early to find the best water and avoid the rush.

Best Spots

Popular access points include:

• Cheesman Canyon Trailhead: Provides easy access to prime fishing spots with deep pools and riffles.
• Gill Trail: Offers access to various sections of the canyon, known for holding large trout.
• Bridge Crossing: Ideal for anglers seeking a mix of calm and fast waters​ 

For real-time data on river conditions, visit the Colorado Division of Water Resources.

Previous River Report

• August Cheeseman Canyon Fishing Report
• July Cheeseman Canyon Fishing Report

Safety Tips

Given the current flows and temperatures, wading can be hazardous. Always inform someone of your plans and avoid crossing the river at unsafe points. Use proper gear, such as a wading staff and boots, to maintain stability in the water. The swift currents can be dangerous, so exercise extreme caution​