Bighorn River Hatch Chart and Best Bighorn River Fly Patterns

Bighorn River Hatches and “Non Hatches”
Bighorn trout have a plentiful supply of food, consisting of “nonhatches” such as crustaceans, annelids(worms) and smaller fish. Bighorn trout also have a steady supply of emerging insects such as mayflies, caddis and terrestrials.  These all take a varying prominence in the trout diet depending on the time of year and river conditions.  It is important to understand these rhythms to pick a fly that will most likely represent what the trout are eating with the most enthusiasm at any particular time.  In this section, we will cover the main food sources.

These “nonhatches” are not insects and are available to the trout year round.  For a good part of the year, and for parts of any given day, “nonhatches”–crustaceans, such as aquatic sowbugs and scud (fresh water shrimp) and worms supply a steady amount of food to feeding trout.  For the bigger trout, smaller fish will also supply a part–or sometimes all–of their diet.  The magnitude of the noninsect food supply is larger for the Bighorn River than for any other Montana river.   The Bighorn River has perfect conditions for these noninsects: alkaline water, a high water mineral content, and plentiful plant life.   Crustaceans and worms thrive in these conditions.  It is important to understand these animals and the flies that best represent these.

Scud - Photo Nick Pionessa	Scuds – thrive off the aquatic vegetation in the river and represent a very important source of food for Bighorn trout that is found in the  river year round. Fishing Tip: While scuds are available year round the bighorn’s trout seem to key on them at certain times.  Finding the right color and size is the key to an angler’s success.  Bighorn River Scud Fly Patterns Bighorn Scud     Spring Creek Scud PoxyBack Scud     UV Scud
Sowbugs	Sowbugs – are a staple on the Bighorn and represent the most abundant crustacean on the Bighorn.  Sowbugs are a similar organism to scuds, except they are more flat and have a dark band on their back. Fishing Tip: Sowbug fly patterns as a group account for more fish caught than any other on the bighorn.  The fly fisher can have success with sowbug patterns any day of the year.  Best Bighorn River Sowbug Flies Ray Charles     Natural Sowbug Soft Hackle SowBug     Tailwater Sowbug
Aquatic Worm	Aquatic Worm – The worm is a tailwater staple and are very plentiful in the Bighorn River. Annelids provide a hearty meal for a trout anytime of the year. Fishing Tip: Color is key to finding an effective worm pattern.  The Worm is especially effective in high water.  Best Bighorn River Worm Flies Two Tone Worm     San Juan Worm Steel Worm     Micro Worm
Baitfish	Baitfish – As the saying goes: “big fish eat smaller fish”. Streamers are effective year round, but most effective in the fall, when the rainbows are bulking up for the oncoming winter and the browns are getting territorial & aggresive before their  spawning season. Fishing Tip: Fish your streamers not only on the banks, but off of drop offs and in the center of the river.  Bighorn River Streamer Patterns Zonker     Bow River Bugger Delektable Screamer    Clouser Minnow

Emerging Insects
The Bighorn River has some of the best dry fly fishing in Montana because of its dense and diverse insect emergence’s. Mayflies, Caddis flies, and terrestrials consistently bring trout to the surface between March and October offering Bighorn River angler’s excellent dry fly fishing.

Adult Midge - Photo Nick P.	Midges – The bread and butter of any tailwater fishery, midges are a significant part of the trout’s diet.  While midges are available to the trout all year, their presence to the fly fisher is most important in late winter and early spring.  Carry imitations of larva, pupa and adult midges in black, red, olive, cream & brown. Hatch: Hatch Year Round Best: February – April Fishing Tip: Carry a seine and stomach pump to properly match the color & size of your imitation with what the trout are eating.  Best Bighorn River Midge Fly Patterns Root Beer Midge     Red Larvae Griffith’s Gnat Zebra Midge
Blue Winged Olive - Photo Nick Pionessa	Blue Winged Olives – Bwo’s are the most significant Mayfly hatch on the Bighorn River.  April and May are the primetime for baetis hatches and again in the fall. The Spring BWOs are size 16-20.  The Fall BWOs (pseudocloens)  are smaller–18, 20, 22. Spring Hatch: April – June Fall: September – October  Fishing Tip: Imitating the BWO swimming nymphs is just as important as fishing the more visible duns to an anglers success. Bighorn River Blue Winged Olive Fly Patterns Wonder Nymph     RS-2 CDC Sparkle Dun Sipper BWO
Pale Morning Dun - Photo Nick Pionessa	The Pale Morning Dun hatch declined a lot during the low water years, but has bounced back.  Water temperature is the main factor for their emergence on the Bighorn.  Water in the mid to upper 50′s is ideal around the end of June into July. Fishing Tip: PMD nymphs are especially effective on the Bighorn, do not over look them.  Trout will key in on the nymph even if they are not feeding on the surface.  Best Bighorn River Pale Morning Dun Flies Wonder Nymph     CDC Cripple PMD Parachute PMD   Mercer’s Poxyback PMD
Trico - Photo Nick Pionessa	Tricos at one time were probably the most famous hatch on the Bighorn. Tricos show themselves on the Bighorn towards the end of August into September. The low water years caused a marked decline in this hatch but in 2009 & 2010 we saw a major rebound. Hatch: August – September  Fishing Tip: Trico fishing occurs during the low clear flows of summer.  Once you have found fish feeding on trico’s be patient and have impeccable presentation. Best Bighorn River Trico Fly Patterns Trico Dun     Male Spinner CDC Trico Female Spinner
Yellow Sally	Yellow Sallies are the only stonefly we fish on the Bighorn.  This hatch had an amazing resurgence on the Bighorn in 2010. Hatch: June – July Fishing Tip: The nymph stage isn’t a real factor to the angler on the Bighorn, fish the hatch with a low riding dry.  Bighorn River Yellow Sallies Flies Para Yellow Sally     Yellow Sally – Elk Hair
Black Caddis	Caddis – Black & Tan - are one of the most consistent hatches on the Bighorn from year to year.  Look for emergence to occur in the afternoon and evenings, but fish can key in on these bugs all day. Hatch: May – September Fishing Tip: Fishing a caddis pupa off the back of a dry can be very effective for both black and tan caddis.  Best Bighorn River Caddis Flies CDC Black Caddis     X-Caddis Caddis Pupa
Flying Ant	Flying Ants & Beetles – At the height of the summer season trout start looking to the surface for terrestrials blowing into the water.   The trout can get very keyed into these big morsels at the right times. Beetles and flying ants are also present throughout the summer. Hatch: July – September  Fishing Tip: Look at the underside fo the natural Grasshoppers and match your pattern accordingly. Bighorn River Ant & Beetle Fly Patterns Para Ant     Power Ant Foam  Beetle
Grasshopper - Photo Nick P.	Grasshoppers - Grasshoppers are cyclic, and the intensity of there presence varies from year to year.  In 2009 we had the grasshopper infestation like no other.  When hoppers are present the trout know it and respond well to imitations. Hatch: July – September  Fishing Tip: During the summer the high grass along the river can be infested with hoppers,  observe the naturals and match your patterns color properly. Bighorn River Grasshopper Fly Patterns Para-Hopper     White Cloud Hopper Sheila Hopper