Green Drake Hatch

Fly Fishing the Green Drake Hatch [Everything You Need to Know]

Often overshadowed by the Salmon Fly and Golden Stone hatch the Green Drake hatch is one of the most notary bug hatches in the west. Many anglers refer to Green Drakes as “trout candy,” because when these bugs begin to hatch, it triggers an all-out feeding frenzy. The trout key in on Green Drakes and munch down the tiny morsels like there is no tomorrow. So what does it take to have success fly fishing the green drake hatch? Below we have outlined everything you need to know about capitalizing on this notary hatch.

What is a Green Drake? 

A western green drake or Drunella Grandis is a large crawling mayfly that can be easily identified for its upright mayfly wings and vibrant green color. They are most often found in size #10-#12 sometimes even an #8 sized fly. The Green Drake can be easily identified from other common mayfly’s like Pale Morning Duns or Blue Wing Olives due to the drake’s larger size and green color. They can be fished as a nymph, emerger, cripple, dun, and spinner. This past blog Fly Fishing Colorado’s Green Drake Hatch outlines the life cycle stages of the Western Green Drake, so be sure to check it out here

One thing to note about Green Drakes that is unlike other mayflies is the Green Drake unfolds its wings 6-12 inches below the surface when emerging. The bug’s wings are also much larger than the smaller mayflies. The wings can take longer to dry on the surface of the water before the bug can fly away. Thus, many anglers fish what is called a Green Drake Cripple pattern which represents this half-hatched bug that may be stuck right below the surface or in the surface film. 

Green Drake Dun Takes Flight
Green Drake Dun Takes Flight

Hatch Timing:

Like other aquatic bug hatches, the hatch timing is related to water temperatures. Most often Green Drakes in the Western United States will begin hatching in late June and into July and then the hatch will typically taper off in August. The start of the summer solstice (June 21st) is generally a good marker date to assume the hatch has started.

At times it can be hard to predict when the Green Drakes are going to hatch. During the peak hatch times, there can be days that the hatch never happens. The hatch is temperamental like many other mayfly hatches, conditions have to be perfect for it to happen. A thunderstorm can put the hatch down while a drought can make it never happen. It can vary day to day at times. We can roughly predict that it is around a water temperature of 58 degrees Fahrenheit when the hatch does come off. 

Time of day plays a big part in the hatch timing as Green Drakes are notorious for hatching at dusk. But, a little bit of cloud cover on a summer day can trigger a solid Green Drake hatch. The trout also will often eat a Green Drake imitation during the middle of the day from the memory of this hatch occurring each evening.

Pro-Guide Tip: For most effective timing, fish the late evening until dusk and even fish this hatch in the dark as the bugs will often hatch into the night. Just remember to put a headlamp in your car and keep it simple with one big dry fly imitation. 

Rainbow on a Green Drake Spinner
Rainbow on a Green Drake Spinner

Hatch Location: 

On the Western Slope of Colorado, the rivers with the most notable Green Drake Hatches are the Roaring Fork and Frying Pan River. The Green Drake hatches on these rivers can last from late June to the end of July, with some opportunity in August in the upper reaches of the Roaring Fork and Frying Pan. For some reason, it is one of the longest-lasting Green Drake hatches in the West. Other rivers with notable Green Drake hatches in the Central Rockies of Colorado is the Upper Arkansas River, Blue River, and Gunnison River.

In recent years anglers have noticed Green Drakes coming off on the Eagle River, Gore Creek, and the Upper Colorado River. It may not be as prolific as the Fork and Pan, but the Green Drakes are beginning to show more life on these rivers. It is really great to see as these mayflies can be a good indicator of the health of the river. 

Pro-Guide Tip: When fishing the Eagle River, Colorado River, or Gore Creek try fishing a Greek Drake dry fly imitation at dusk to try to trigger a larger fish to eat on the surface. At times these larger fish will key in and selectively eat these larger Green Drakes instead of eating some of the other common fare like Caddis. 

Brown Trout on the Drake Dry
Brown Trout on the Drake Dry

Tips and Techniques:

Less Competition on the Water: One aspect to note about the Green Drake hatch is when the hatch occurs it is typically not very prolific like the caddis hatch or salmon fly hatch where there are thousands of natural bugs flying around. This means that your fly doesn’t have as much competition on the water from the naturals so it can be easier to get a trout to rise to your fly. So with this in mind fly selection is less important. It can also mean that your presentation has to be drag-free as the trout have more time to look at the fly before eating it.

Fly Action: Due to their larger size green drakes aren’t the most graceful bug on the water. For anglers, this means that a little bit of added action to the dry fly can provoke a strike. So don’t be afraid to move the fly around like a caddis and remember to pick up slowly to cast again as many fish will strike on the slightest sign of movement. 

Tippet Size: Typically you are fishing size 8-12 fly patterns so ditch the 5x and throw on some 3x and even 2x tippet. It will help turn over the leader better. And will prevent break-offs especially when you hook the larger trout that are keyed in on Green Drakes. 

Understand the Green Drake Life Cycle: As outlined in the Fly Fishing Colorado’s Green Drake Hatch blog, there are 5 main stages of a green drake life cycle. At times the fish are keyed into a specific stage of this life cycle. On warmer days the Green Drakes will emerge and their wings will dry faster in the sun and the fish will key in on the dun stage of their life cycle. While on wetter colder days the fish may be keyed in on the cripple stage of the drake as these bugs are caught up in the surface film more so than the dun stage. So be sure to assess the day, the trout’s feeding behavior, and be ready to switch patterns as the hatch progresses from emerger/cripples to dun to spinners.

Pro-Guide Tip: Rig a dry fly green drake imitation followed by a couple of feet of tippet to a cripple green drake imitation. As mentioned above Green Drakes unfold their wings below the surface and are typically on the surface for longer periods of time. This means a cripple imitation of green drake can be an effective fly pattern. The cripple can often be hard to see on the surface, so a dry fly in front of it can be a great way to see the cripple and potentially get an eat on the dry. It can be deadly in riffles and rock gardens where turbulent water is present. 

Fly Recommendations:

Outlined below are the suggested flies for the 5 different stages of the Green Drake life cycle. All suggested patterns are sized #8-#14 with the most common sizes of fly being #10-12. It is suggested to have a variety of each stage to be prepared to fish the Green Drake hatch.


Nymph Patterns: Twenty Incher, Chartreuse Copper John, Prince Nymph, Formerly Known Prince Nymph, Tungsten Salvation Nymph Emerald, Two-Bit Drake, Jigged Tungsten Drake, and Mercers Poxyback Green Drake.


Emerger Patterns: CDC Green Drake Emerger and other unweighted Green Drake nymph patterns.


Cripple Patterns: Green Drake Cripple, Cripple Foam Drake, and Film Critic Green Drake.


Dun Patterns: Green Drake Hairwing, Green Chubby Chernobyl, Green Parawulff, Neversink Drake, Lawsons Stanard Green Drake, and CDC Comparadun Green Drake. 

Spinner Patterns: Last Chance Drake, Green Drake Spinner, and Clear Wing Spinner.

Fly fishing the Green Drake hatch can be some of the most rewarding dry fly fishing of the year as the biggest fish in these river systems come out in numbers to feed heavily on these bugs. The water temperatures allow for the trout to feed consistently, fight hard, and be safely released knowing that will live to feed another day. 

The guides at Vail Valley Anglers have been guiding the Green Drake hatch on the Roaring Fork for over 30 years. If you are interested in booking a trip to try and fish this notable bug hatch give the shop a call at 970.926.0900 to check the availability of our professional guides. We prefer float fishing the lower Roaring Fork to effectively fish this hatch. This trip is only available in a full day, suggested dates are from June 21st-July 21st but can vary year to year and day to day. Check out the Roaring Fork Fishing report here.

Patrick Perry, Content Contributor, and Former Guide, @patperry