River Resources

Everything you need to know about the Bighorn

Bighorn River At-a-Glance

Water Type: Fertile tailwater, year-round trout fishing
Trout Species: ~3,500 Brown & Rainbow Trout per mile
Fishing Seasons: Open Year-Round
River Miles: ~35 miles of productive trout water
Best Access: Afterbay Dam, Three Mile, Bighorn, Mallards, Two Leggins
Primary Hatches: Midges, BWOs, PMDs, Black Caddis, Tricos
Closest Airport: Billings Int'l Airport
Angler Facilities: Fort Smith, MT

Seasons on the Bighorn

Spring (March – May)

One of the most productive times to fish. Nymphing with sowbugs + midge or BWO nymphs. Warmer temps = Midges & BWOs hatching for dry fly action.

Summer (June – August)

Black Caddis, Tricos, Sallies, PMDs, terrestrials. Both dry fly & nymph tactics. Warm days = wading or wet wading.

Fall (Sept – Nov)

Productive nymph & dry fly fishing continues. Streamers turn on for browns. Late-summer hatches linger & Pseudos (tiny BWOs) can appear on overcast days.

Bighorn Hatch Chart

This chart outlines the key insect emergences throughout the year. Use it to plan your trip around peak hatch times—or carry the right flies to match the hatch on any given day. Weather and water conditions can shift timing slightly, so always stay flexible!

Equipment Checklist

Fly Rods

Dry Fly Rods: 8’6” 4wt, 9’ 4wt, or 9’ 5wt
Nymph Rods: 9’6” 5wt or 6wt
Streamers: 9’ 6–7wt rods
Disc-drag reels, large arbor for quick retrieval

Fly Lines

Nymph Lines: Long belly (SA Anadro, etc.) for easy mending
Dry Lines: Delicate taper for match-the-hatch or bullet taper for hoppers
Streamers: Sink tips or 10–24 ft sinking heads to get down fast

Leader & Tippet

9’ 3x or 4x (nymph), 9’ 4x or 5x (dry)
Tippet spool range: 2X–6X covers all
Bring strike indicators, split shot, floatant, etc.

Fly Fishing Apparel

Waders & Boots (spring/fall), or wet-wading in summer
Sun-protective shirt, hat, sunglasses, sunscreen
Always pack a waterproof rain jacket

A Glimpse of the Bighorn

Explore the beauty of our river and the excitement of a day on the water