Colorado Fly Fishing Hatch Charts

Colorado's rivers, creeks and streams offer the fly fishing angler a myriad of great insect hatches throughout the season. To take out a little guesswork, you can consult this fly hatch chart before you head out. Hatches vary and if you utilize these localized Colorado fly fishing hatch charts you can get a good general understanding. To make it even easier, our expert fly fishing guides are on the water every day and can take you where the best hatches are occurring.

Colorado Hatch Conditions

Caddisflies

Insects: American Grannom
Color: Bright Green to Greenish Brown
Dates: Mar 1 – May 15
Emergence: Early Morning & Afternoon
Size: 10-14
Spinner Fall: NA
Illustrations © The Flyfisher Group 
Insects: Great Gray Spotted Sedge
Color: Gray Green to Olive Brown
Dates: Jun 1 – Jul 15
Emergence: Sporadic
Size: 10-12
Spinner Fall: NA
Illustrations © The Flyfisher Group 
Insects: Green Sedge
Color: Olive to Gray Brown
Dates: Jul 15 – Sep 30
Emergence: Morning & Afternoon
Size: 12-14
Spinner Fall: NA
Illustrations © The Flyfisher Group 
Insects: Little Black Sedge
Color: Chocolate to Black
Dates: Jul 15 – Sep 30
Emergence: Sporadic
Size: 16-18
Spinner Fall: NA
Illustrations © The Flyfisher Group 
Insects: Little Plain Brown Sedge
Color: Brown to Chocolate
Dates: Jun 15 – Aug 30
Emergence: Sporadic
Size: 14-16
Spinner Fall: NA
Illustrations © The Flyfisher Group 
Insects: Little Sister Sedge
Color: Green to Greenish Brown
Dates: May 15 – Aug 30
Emergence: Afternoon & Evening
Size: 14-16
Spinner Fall: NA
Illustrations © The Flyfisher Group 
Insects: Little Tan Short Horn Sedge
Color: Dark Brown to Yellow
Dates: Mar 1 – Aug 30
Emergence: Sporadic
Size: 14-16
Spinner Fall: NA
Illustrations © The Flyfisher Group 
Insects: Little Western Dark Sedge
Color: Dark Brown
Dates: Jun 1 – Aug 15
Emergence: Mid Day
Size: 16-18
Spinner Fall: NA
Illustrations © The Flyfisher Group 
Insects: Micro Caddis
Color: Yellow, Orange or Brown
Dates: Jun 15 – Oct 15
Emergence: Sporadic
Size: 20-22
Spinner Fall: NA
Illustrations © The Flyfisher Group 
Insects: October Caddis
Color: Orange Tan to Grayish Black
Dates: Sep 1 – Oct 30
Emergence: Shallows, Afternoon & Evening
Size: 8-10
Spinner Fall: NA
Illustrations © The Flyfisher Group 
Insects: Spotted Sedge
Color: Brownish Yellow
Dates: May 15 – Sep 30
Emergence: Sporadic
Size: 10-12
Spinner Fall: NA
Illustrations © The Flyfisher Group 

Mayflies

Insects: Blue Winged Olive
Color: Light Olive Brown to Brown Olive
Dates: Mar 1 – Nov 15
Emergence: Clouds & warmest part of day
Size: 16-18
Spinner Fall: Evening
Illustrations © The Flyfisher Group 
Insects: Brown Drake
Color: Dark Brown to Blackish
Dates: Jun 15 – Jul 15
Emergence: Evening
Size: 10-12
Spinner Fall: Late Evening
Illustrations © The Flyfisher Group 
Insects: Callibaetis Speckled Dun
Color: Tannish Olive to Olive Gray
Dates: Jun 1 – Aug 30
Emergence: Cloudy, Late Morning
Size: 14-16
Spinner Fall: Late Afternoon
Illustrations © The Flyfisher Group 
Insects: Early Pale Morning Dun (PMD)
Color: Olivish Yellow to Yellowish Pink
Dates: Jun 1 – Sep 15
Emergence: Mid Morning to Early Afternoon
Size: 16-22
Spinner Fall: Late Evening
Illustrations © The Flyfisher Group 
Insects: Ginger Quill
Color: Pale Cream to Whitish
Dates: Jul 1 – Sep 15
Emergence: Morning
Size: 14-16
Spinner Fall: Evening
Illustrations © The Flyfisher Group 
Insects: Gray Drake
Color: Gray
Dates: Jun 1 – Nov 30
Emergence: Late Morning
Size: 14-16
Spinner Fall: Evening
Illustrations © The Flyfisher Group 
Insects: Iron Blue Quill
Color: Light Olive Tan to Blue Gray
Dates: Jun 1 – Aug 15
Emergence: Warmest part of day
Size: 20-22
Spinner Fall: Evening
Illustrations © The Flyfisher Group 
Insects: Late Pale Morning Dun (PMD)
Color: Creamish Olive to Yellowish
Dates: Jun 15 – Jul 15
Emergence: Early Morning
Size: 16-18
Spinner Fall: After Afternoon
Illustrations © The Flyfisher Group 
Insects: Mahogany Dun
Color: Reddish Brown to Blackish Brown
Dates: Sep 1 – Oct 31
Emergence: Early Afternoon
Size: 16-18
Spinner Fall: Late Evening
Illustrations © The Flyfisher Group 
Insects: Micro Blue Winged Olive (BWO)
Color: Pale Olive Green to Blue Gray
Dates: Jun 1 – Nov 30
Emergence: Clouds & warmest part of day
Size: 22-26
Spinner Fall: Evening
Illustrations © The Flyfisher Group 
Insects: Pink Pale Morning Dun
Color: Pink to Orangish to Rusty Red
Dates: Aug 1 – Sep 15
Emergence: Daytime
Size: 14-16
Spinner Fall: Early Morning
Illustrations © The Flyfisher Group 
Insects: Red Quill
Color: Reddish Brown
Dates: Jun 15 – Sep 30
Emergence: Mid Morning
Size: 14-16
Spinner Fall: Evening
Illustrations © The Flyfisher Group 
Insects: Slate Winged Drake
Color: Brown to Slate Gray
Dates: Jun 15 – Aug 1
Emergence: Early Afternoon
Size: 16-12
Spinner Fall: Evening
Illustrations © The Flyfisher Group 
Insects: Trico
Color: Black
Dates: Jul 15 – Sep 15
Emergence: Morning
Size: 22-26
Spinner Fall: Early Afternoon
Illustrations © The Flyfisher Group 
Insects: Western Black Quill
Color: Purplish Black to Grayish Brown
Dates: Apr 1 – Jun 30
Emergence: Mid Morning
Size: 14-12
Spinner Fall: Evening
Illustrations © The Flyfisher Group 
Insects: Western Green Drake
Color: Dark Olive
Dates: Jun 1 – Aug 1
Emergence: Cloudy, 1-4 pm
Size: 8-12
Spinner Fall: Evening
Illustrations © The Flyfisher Group 

Midges

Insects: Black Midge
Color: Blackish to Black
Dates: Apr 1 – Nov 15
Emergence: All Day
Size: 18-20
Spinner Fall: 2-3 Hours
Illustrations © The Flyfisher Group 
Insects: Chocolate Brown Midge
Color: Brown to Chocolate
Dates: Feb 15 – Dec 15
Emergence: All Day
Size: 20-22
Spinner Fall: 2-3 Hours
Illustrations © The Flyfisher Group 
Insects: Micro Black Midge
Color: Blackish to Black
Dates: Mar 1 – Nov 15
Emergence: Morning
Size: 22-26
Spinner Fall: 2-3 Hours
Illustrations © The Flyfisher Group 
Insects: Snow Midge
Color: Gray to Charcoal
Dates: Jan 1 – Dec 31
Emergence: Warmest part of day
Size: 24-28
Spinner Fall: 2-3 Hours
Illustrations © The Flyfisher Group 

Stoneflies

Insects: Giant Golden
Color: Brownish Yellow
Dates: Jun 1 – Aug 1
Emergence: Follows Salmonflies
Size: 14-18
Spinner Fall: NA
Illustrations © The Flyfisher Group 
Insects: Micro Black
Color: Dark Brown to Black
Dates: Jan 1 – May 15
Emergence: 38-44° Water Temps Heat of Day
Size: 18-22
Spinner Fall: NA
Illustrations © The Flyfisher Group 
Insects: Micro Yellow
Color: Greenish Yellow to Yellow
Dates: Jun 1 – Aug 30
Emergence: 46-54° Water Temps Morning
Size: 18-22
Spinner Fall: NA
Illustrations © The Flyfisher Group 
Insects: Salmon Fly
Color: Black to Reddish Brown
Dates: May 15 – Jul 15
Emergence: 50-60° Water Late Morning on
Size: 4-8
Spinner Fall: NA
Illustrations © The Flyfisher Group 
Insects: September Stone
Color: Reddish Brown with Orange belly
Dates: Aug 15 – Oct 31
Emergence: Early Afternoon to Evening
Size: 4-10
Spinner Fall: NA
Illustrations © The Flyfisher Group 
Insects: Skwala Stone
Color: Dark Brown to Yellow Olive
Dates: Mar 1 – May 15
Emergence: 38-47° Water Temps, Late afternoon and evening. Riffles and bankwater near foliage.
Size: 6-12
Spinner Fall:
Illustrations © The Flyfisher Group 
Insects: Small Western
Color: Brownish
Dates: May 15 – Jul 15
Emergence: 46-56° Water Temps
Size: 14-18
Spinner Fall: NA
Illustrations © The Flyfisher Group 
Insects: Winter Black
Color: Black Brown to Reddish Olive, Mottled Brown
Dates: Apr 1 – Aug 15
Emergence: Cold Mountain Streams and Small Ponds
Size: 18-22
Spinner Fall: NA
Illustrations © The Flyfisher Group 
Insects: Yellow Sally
Color: Pale Yellow to Pinkish Yellow
Dates: Jun 15 – Aug 30
Emergence: Morning to Early Afternoon
Size: 2-8
Spinner Fall: NA
Illustrations © The Flyfisher Group 

Terrestrials

Insects: Beetle
Color: Brownish to Black
Dates: May 1 – Nov 30
Emergence: All Day
Size: 10-18
Spinner Fall: NA
Illustrations © The Flyfisher Group 
Insects: Black & Red Ant
Color: Red & Black
Dates: Jul 1 – Sep 30
Emergence: All Day
Size: 18-20
Spinner Fall: NA
Illustrations © The Flyfisher Group 
Insects: Black Ant
Color: Black
Dates: May 1 – Nov 15
Emergence: All Day
Size: 20-24
Spinner Fall: NA
Illustrations © The Flyfisher Group 
Insects: Cricket
Color: Brownish Olive to Black
Dates: Jun 1 – Nov 30
Emergence: Twilight & Dusk
Size: 8-16
Spinner Fall: NA
Illustrations © The Flyfisher Group 
Insects: Dog Day Cicadas
Color: Black & Orange
Dates: Jul 1 – Aug 31
Emergence: Varied
Size:
Spinner Fall: NA
Illustrations © The Flyfisher Group 
Insects: Flying Black Ant
Color: Black
Dates: Aug 15 – Sep 15
Emergence: Mid Afternoon
Size: 14-18
Spinner Fall: NA
Illustrations © The Flyfisher Group 
Insects: Grasshopper
Color: Green to Brownish Tan
Dates: May 15 – Nov 15
Emergence: All Day
Size: 2-14
Spinner Fall: NA
Illustrations © The Flyfisher Group 
Insects: Red Ant
Color: Red to Orangish
Dates: May 1 – Oct 15
Emergence: All Day
Size: 18-22
Spinner Fall: NA
Illustrations © The Flyfisher Group