05/14/22 Eleven Mile Canyon

Trip Captain :  Dwyne Combs

Email: Trips@flyfisherscolorado.com

Date Of trip; May 14,2022

We will meet at the Idlewiild Picnic Area, just a short distance befor you get to  the Dam in the parking area at 7:30AM. This is scheduled as a day trip and is about a 2.5 hr. drive from the Denver


11 Mile Canyon is one of Colorado's most famous trout fisheries in every way possible. As a fishery that boasts more than 3,000 fish per mile and is known as one of the most scenic stretches of the South Platte River, you can assume that these trout are seeing some sort of angling pressure 365 days a year. The rainbow trout, brown trout, and cutthroat trout that call this river home are not the easiest fish to entice. Make sure you have a large assortment of small midges and baetis patterns for the winter months and shoulder seasons. Summertime in the canyon can produce some of the most abundant dry fly hatches you will ever see in your lifetime. No matter what time of year you will be fishing 11-mile canyon, tippet selection will make or break your success. Small tippet sizes for both nymph fishing and dry fly fishing will increase your chances of fooling these fish to eat a fly. One of the biggest keys to success in the canyon is your eyes. Make sure to have a good pair polarized sunglasses and use sight fishing to your advantage.

 Image result for Eleven Mile Canyon Camping



There are lots of flies for 11-mile canyon and the right fly selection is important.  Focus on these colors and sizes of the following insects and refer to the hatch charts for the right time of year to use them:

  • Midge Nymphs, Emergers & Dries
    • Colors: Black, White, Olive
    • Sizes: #18 – #26
  • Mayfly Nymphs, Emergers & Dries
    • Colors: Olive, Grey, Yellow, Black
    • Sizes: #18 – #24
  • Caddis Nymphs, Emergers & Dries
    • Colors: Olive, Brown
    • Sizes: #14 – #18
  • Stonefly Nymphs & Dries
    • Colors: Yellow, Brown, Black
    • Sizes: #8 – #14
  • San Juan Worms
    • Colors: Pink, Red, Brown
    • Sizes: #10 – #16
  • Scuds
    • Colors: Grey, Pink, Orange, Olive
    • Sizes: #14 – #18
  • Hoppers
    • Colors: Yellow, Tan, Olive
    • Sizes: #10 – #16
  • Ants
    • Colors: Black, Red
    • Sizes: #14 – #18


  • Fish: Many Large-Sized Fish
  • Popularity: High
  • Difficulty: Hard
  • Accessibility: Easy
  • Best Techniques: Nymphs
  • Best Seasons: Year Round
  • River Type: Medium Tailwater
  • Fish Types: Rainbow Trout, Cutbow Trout, Brown Trout, Cutthroat Trout
  • Dog Friendly: Yes but Leashed
Located in the South Platte River Basin near Lake George, CO




Knowing what flies to use is only have the battle. You have to know when the insects are active on the water and when it's likely the trout are feeding on them. Refer to our hatch charts below to understand when the insect categories and some of the possible hatches on the river.


Midges hatch year round, but their importance is from September through winter into April. During the warmer months, the trout often focus on larger insects as they are more active on the water like mayflies, caddis and stoneflies.

  • Colors: Black, White, Gray, Cream, Olive, Red, Brown, Blue, and Purple
  • Sizes: #16 - #24


Aside from Blue wing olives, mayflies are active most commonly from May to August in Colorado. There are many different mayfly hatches found on most rivers and the most common are listed below.

  • Blue Wing Olive: September throut winter to April
    • Colors: Green/Olive
    • Sizes: #16-24
  • Pale Morning Dun: June to Mid September
    • Colors: White, Yellow
    • Sizes: #14 - #20
  • Trico Mayflies: Mid July to Mid September
    • Colors: Black, White, Grey
    • Sizes: #18 - #26


Caddis hatch starting early in May and continue to the end of October.

  • Colors: Olive, Green, Yellow, Tan, Orange, Brown and Black.
  • Sizes: #10 - #20


We have some great stonefly hatches in Colorado and while not all rivers carry all species of salmonflies, you can often fish stonefly adult patterns with confidence from May to September. Start off in bigger sizes and get smaller till September hits (size 8 - 16)

  • Golden Stone: June to August
    • Colors: Yellow, Tan
    • Sizes: #8 - #14
  • Yellow Sally Stonefly: Mid June to August
    • Colors: Yellow, Tan
    • Sizes: #12 - #18


Terrestrials don't hatch since they are out of the water, but they can have importance starting in Mid April and ending in September.

  • Ant Patterns: Mid April - September
    • Colors: Black, Tan, Red, Brown
    • Sizes: #14 - #18
  • Beetles: May to September
    • Colors: Black, Blue, Purple
    • Sizes: #14 - #18
  • Hoppers: June to September
    • Colors: Tan, Yellow, Olive, Red, Pink, Purple
    • Sizes: #8 -#16
  • Flying Ants: Mid August to Mid September
    • Colors: Red, Black
    • Sizes: #14 - #18


 Sean O'neill has had a family situation come up and will be in Texas when his trip to 11 Mile Canyon is scheduled to take place. I (Dwyne Combs ) am going to fill in for him , and he forwarded some information to me that has served him welll in the Canyon in the past. 

He recommends meeting up at the Idlewild Picnic Area, which is just a short distance befor you get all the way in to the Dam.

Pat Dorsey does a nice writeup of this fishery on his website and you can monitor the flows here. Just as Dorsey says, May is an amazing time to fish this section and the yellow sally stonefly and caddis hatch should be in full swing as the water / weather is warming up.

  • I’ve had some incredible days on the river here fishing dry droppers in the middle of May – mainly stimulators and elk hair caddis drys and don’t discount the BWOs either.  
  • I have had a ton of success with size 20-24 foam wing emerger / chocolate thunder or small flashback pheasant tails trailing my dries or on my nymph rigs
  • If there’s not much hatch activity I’ll run a triple nymph rig early then switch to a dry double dropper around 9am. Other nymphs that I’ve had success on all match what Dorsey says in his writeup: small sparkle wing rs2s, baetis emergers, red thread midge, zebra midge, caddis pupa, and soft hackles

He also included a map , but for some reason i cant copy it from the email to the blog post , so will print a few out and bring with me on Sat.  Hope to see you all there , and we will have brats at lunch so bring some sort of side dish or chips .