Hatch Charts

The following represents major hatches as they occur in the area. Before streams clear, drop and warm sufficiently for hatches to appear consistently, anglers should fish nymphs and streamers. Early season hatches will appear at the warmest time of the day. As air and water temperatures rise during the season, hatches will occur earlier in the day. Late season angling (September/October) is often most productive with large nymphs and streamers as spawning fish become more territorial.



STONEFLIES

Salmon Fly -- (Pteronarcys californica)
Progressive hatch moving upstream several miles per day as water temperatures rise.

Madison River - Ennis to Hebgen Dam - June 25 to July 15
Yellowstone River - July
Gallatin River - June 15 to July 15

Golden Stone -- (Hesperopela pacifica)
Madison River - July
Yellowstone River - June 20 to July 20
Gallatin River - July

Yellow Sally -- (Isoperia & Suwallia pallidula)
Firehole River - June
Madison River - July 15 to August 15
Gallatin River - July 15 to August 15

MAYFLIES
Pale Morning Duns -- (Ephemerella inermis & infrequens)
Firehole River - June 1 to July 10
Madison River - (YNP) June 10 to July 15
Madison River - July 1 to August 15
Yellowstone River - July 5 to September 10

Western Green Drake -- Ephemerella grandis)
Madison River - (YNP) June 15 to July 10

Brown Drake -- (Ephemera simulans)
Gibbon River - June 25 to July 10

Small Western Green Drake -- (Ephemerella flavilinea)
Madison River - July 15 to August 10
Yellowstone River - July 20 to August 10

Gray Drake -- (Siphlonurus occidentalis)
Slough Creek - July 15 to September 15
Yellowstone River - July 15 to September 15

Callibaetis -- (Callibaetis americanus)
Hebgen Lake - July 15 to September 15

Trico -- (Tricorythodes minutu)
Hebgen Lake - July 10 to September 15
Madison River - August to September 30

Blue Wing Olive -- (Baetis, many species)
Firehole River - June, September, October
Madison River - September 1 to October 15
Yellowstone River - August 1 to October 30

CADDIS - many species
Firehole River - June 5 to July 15, September 10 to October 20
Madison River - June 25 to August 20
Gallatin River - July 1 to August 20
Yellowstone River - July 15 to August 30

TERRESTRIALS
Hoppers, ants, beetles, crickets
All streams July 5 to Sept 30