Cheesman Canyon
14 Day Forecast: Look for sporadic hatches of midges and the occasional olive and caddis.
Effective Patterns: #20-22 Top Secret Midge, #20-22 Manhattan Midge, #20-22 Jujubaetis, #20-22 Top Secret Baetis, #20-24 Chocolate Foam Wing Emerger, #18 Micro Egg, #20-22 Red Larva, #20 Mercurry Blood Midge, #18 Micro San Juan Worm, #16 Orange UV Scud, #20 Flashback Mercury Black Beauty, #18 Buckskin, #20- #16-20 Mole Fly, #20 Mathew's Sparkle Dun, and #20 Parachute Blue-Winged Olive.
Measurements
Stream Tips from Pat Dorsey for Fly Fishing Cheesman Canyon in Colorado
The picturesque boulder-filled Cheesman Canyon portion of the South Platte River is considered by many one of the most pristine fisheries in the world. This area, often times simply referred to, as “the Canyon” is an experience you’ll never forget. It’s the perfect scenario, magnificent beauty in combination with great fly fishing.
The South Platte River carves its way through a granite canyon lined with ponderosa pines, willows, fallen tree trunks, and various other assorted ground foliages. Boulders as big as Volkswagens Beetles create structure for the super-selective trout residing in the river. Mule Deer, Black Bear, Raccoons, Mountain Lyons, and Bald Eagles all add to the experience. Anglers can expect to catch mostly large rainbows supplemented with a few nice brown trout. The aforementioned “canyon” is as technical as they get, and if you can catch trout here, you can catch them anywhere in the world. This three-mile section is primarily a nymphing fishery requiring tiny midge and mayfly imitations with fine 5 and 6X tippets. Ideal flows for Cheesman Canyon are between 250 and 400 cfs. The regulations are flies and lures only. All fish must be returned to the water immediately.
Cheesman Canyon is one of the best tailwaters in the country. There's a common belief among "canyon regulars" that if you can catch fish on the South Platte River, you can fool fish anywhere in the world. There's no substitution for good technique in Cheesman Canyon.
Tips & Other Information:
Outflows are currently 191 cfs below Cheesman Reservoir and “class is back in session”. Denver Water dropped the outflows yesterday as the city has been getting some much needed rain in the metro area and outlying region. I would not be suprised if they drop outflows further as the week progress if we get more rain. Today’s forecast is for another round of severe weather so be careful out there and keep your wits about you. Cheesman Reservoir is currently at 74% capacity as of this morning. It’s dropping fast because inflows are only 121 cfs. They came up a bit with the lastt two days rainfall. The hatches have been light which is complicating things further. We’re seeing a few midges in the morning, then the occasional “olive”, PMD, and caddis mid day. There’s not enough bugs to really get the super-selective hatch-driven Cheeesman Canyon trout going. The browns are tight-lipped and hiding and the rainbows are feeding opportunistically. Midge larvae (Mercury Midge, pale-olive larva, etc.) have been my top producers as of late. Water temps are reaching the mid 50’s later in the afternoon. Revised 7/30/26