bighorn-river

Bighorn River (Montana) is a river in Montana.

It ranks #4 among the 17 waters of Montana in the registry, and is of national prominence.

Its official name is Bighorn River.

Also called The Horn, Big Horn River and The Bighorn.

Fished for trout (inferred from the species listed).

Species: rainbow trout and brown trout.

USGS GNIS record: 779903.

Stretches: Afterbay to Three Mile, Three Mile to Bighorn Access, Bighorn Access to Mallard's Landing and Mallard's Landing to Two Leggins.

Access points: Afterbay, Bighorn Access, Three Mile Access, Mallard's Landing and Two Leggins.

Holes: Breakfast Hole, Hot Dog Run and Duck Blind.

Features: Yellowtail Dam.

Red Cliffs (hole). It is fishable.

It is on the stretch Afterbay to Three Mile.

Arapooish (access). It is fishable and launchable. Big Sky Fishing: Arapooish FAS, river mile 40.7. Lower river below Two Leggins; far less fished than the tailwater. Also called Arapooish FAS.

It is upstream of Grant Marsh.

It is downstream of Two Leggins.

Bay of Pigs (hole). It is fishable. Single source (yellowstone.fishing).

Drive-In (hole). It is fishable. Single source (yellowstone.fishing).

General Custer (access). It is fishable and launchable. Big Sky Fishing: river mile 24.2. Also called General Custer FAS.

It is upstream of Manuel Lisa.

It is downstream of Grant Marsh.

Glory Hole (hole). It is fishable. Single source (yellowstone.fishing).

Grant Marsh (access). It is fishable and launchable. Big Sky Fishing: river mile 31.7. Also called Grant Marsh FAS.

It is upstream of General Custer.

It is downstream of Arapooish.

Holly's (hole). It is fishable. Single source; exact position on the river not stated. Also called Hollys.

Manuel Lisa (access). It is fishable and launchable. Big Sky Fishing: river mile 1.8, near the Yellowstone River confluence. Also called Manual Lisa FAS and Manuel Lisa FAS.

It is upstream of Yellowstone River confluence.

It is downstream of General Custer.

Meat Hole (hole). It is fishable. Single source (yellowstone.fishing); listed with The Aquarium, Bay of Pigs, Drive-In, Glory Hole.

Soap Creek (hole). It is fishable. Single source (named as a 'stop' by BB); position not stated.

St. Xavier Bridge (access). It is fishable and launchable. Big Sky Fishing selected river miles: St. Xavier Bridge Access Site at river mile 68 (between Bighorn FAS at 71.7 and Mallards Landing at 62.9). Also called St. Xavier Bridge Access Site.

It is upstream of Mallard's Landing.

It is downstream of Bighorn Access.

The Aquarium (hole). It is fishable. Single source (yellowstone.fishing).

Yellowstone River confluence (confluence). It is fishable. Big Sky Fishing: confluence with the Yellowstone River at river mile 0. Shared with the Yellowstone River (Montana) record.

It is downstream of Manuel Lisa.

Float: 3 Mile to 13 Mile (Bighorn Access), from Three Mile Access to Bighorn Access.

Float: Mallard's Landing to Two Leggins, from Mallard's Landing to Two Leggins, 10 miles.

Float: Bighorn Access to Mallard's Landing, from Bighorn Access to Mallard's Landing, 10 miles.

Float: Afterbay to 3 Mile, from Afterbay to Three Mile Access.

Sourced from 7 independent fly sites.

Sources: biggiesbugs.wordpress.com, bighornangler.com (retrieved 2026-10-20), bigskyfishing.com, Fly Anglers Online, Fly Anglers Online (2), flyfishingbozeman.com, National Park Service, The Perfect Fly Store, riverreports.com, totalflyfishing.com and yellowstone.fishing.

Hatches

Pale Morning Dun

Stage: nymph, dun. Well sourced. Sources give different windows; this shows the range.

  1. Jan
  2. Feb
  3. Mar
  4. Apr hatching
  5. May hatching
  6. Jun hatching
  7. Jul hatching
  8. Aug hatching
  9. Sep
  10. Oct
  11. Nov
  12. Dec

Reported windows differ: the main source gives mid-June through July, starting at 58F, in riffles and swifter water, size 14-18 (mostly 16/18); a templated chart lists May-August with a late-April start.

Sources: Montana Angler, Montana Angler, Montana Angler, The Fly Fishing Place, The Fly Fishing Place, The Fly Fishing Place

Blue-Winged Olive

Stage: emerger. Well sourced.

  1. Jan
  2. Feb
  3. Mar hatching
  4. Apr hatching
  5. May hatching
  6. Jun
  7. Jul
  8. Aug
  9. Sep
  10. Oct
  11. Nov
  12. Dec

Early March through May, and again mid-September well into October (separate fall entry). Strongest on overcast days; spring size 14-16, fall 16-22. A templated chart lists March-May and September-November as primary.

Sources: Montana Angler, Montana Angler, Montana Angler, The Fly Fishing Place, The Fly Fishing Place, The Fly Fishing Place

Yellow Sally

Stage: nymph. Well sourced.

  1. Jan
  2. Feb
  3. Mar
  4. Apr
  5. May
  6. Jun hatching
  7. Jul hatching
  8. Aug
  9. Sep
  10. Oct
  11. Nov
  12. Dec

Nymphs are eaten daily (size 8-16, mostly 10/12); adults fly erratically; no months given. A templated chart lists June-July.

Sources: Montana Angler, Montana Angler, Montana Angler, The Fly Fishing Place, The Fly Fishing Place, The Fly Fishing Place

PMD, Black Caddis, Tan Caddis, Trico, hoppers (July)

Well sourced.

  1. Jan
  2. Feb
  3. Mar
  4. Apr
  5. May
  6. Jun
  7. Jul hatching, peak
  8. Aug
  9. Sep
  10. Oct
  11. Nov
  12. Dec

Peak: July is best and most consistent dry-fly month

Sources: bighornangler.com

October Caddis

Well sourced.

  1. Jan
  2. Feb
  3. Mar
  4. Apr
  5. May
  6. Jun
  7. Jul
  8. Aug
  9. Sep hatching
  10. Oct hatching, peak
  11. Nov
  12. Dec

Peak: mid-October

As early as late September; size 8-10; adults rarely seen.

Sources: Montana Angler, Montana Angler, Montana Angler

Blue-Winged Olive (fall)

Well sourced.

  1. Jan
  2. Feb
  3. Mar
  4. Apr
  5. May
  6. Jun
  7. Jul
  8. Aug
  9. Sep hatching
  10. Oct hatching
  11. Nov
  12. Dec

Size 16-22.

Sources: Montana Angler, Montana Angler, Montana Angler

Trico and Pseudocloeon (fall)

Well sourced.

  1. Jan
  2. Feb
  3. Mar
  4. Apr
  5. May
  6. Jun
  7. Jul
  8. Aug
  9. Sep hatching
  10. Oct hatching
  11. Nov hatching
  12. Dec

Technical dry-fly fishing from September to early November; excellent Baetis hatches in November.

Sources: bighornangler.com

Midge

Stage: larva. Well sourced. Sources give different windows; this shows the range.

Months: October to April

  1. Oct hatching
  2. Nov hatching
  3. Dec hatching
  4. Jan hatching
  5. Feb hatching
  6. Mar hatching
  7. Apr hatching
  8. May
  9. Jun
  10. Jul
  11. Aug
  12. Sep

Year-round; trout take them subsurface year-round; size 16-26, mostly 18-22. A templated chart lists January-April and October-December as primary (size 20-26).

Sources: Montana Angler, Montana Angler, Montana Angler, The Fly Fishing Place, The Fly Fishing Place, The Fly Fishing Place

Grasshoppers, ants and beetles

Stage: adult. Well sourced.

  1. Jan
  2. Feb
  3. Mar
  4. Apr
  5. May
  6. Jun
  7. Jul hatching, peak
  8. Aug
  9. Sep
  10. Oct
  11. Nov
  12. Dec

Peak: dominate by late July

Hoppers size 8-12, ants and beetles 14-18; dominant by late July. A templated chart has hoppers peaking in August and lasting to mid-September.

Sources: Montana Angler, Montana Angler, Montana Angler, The Fly Fishing Place, The Fly Fishing Place, The Fly Fishing Place

Caddis (tan and black)

Stage: adult. Well sourced. Sources give different windows; this shows the range.

  1. Jan
  2. Feb
  3. Mar
  4. Apr hatching
  5. May hatching
  6. Jun hatching
  7. Jul hatching
  8. Aug hatching
  9. Sep hatching
  10. Oct
  11. Nov
  12. Dec

Reported windows differ: the main source has tan and black caddis both very strong in July, a few weeks after the PMDs (black most prolific just before dark, tan all day; size 16-22) and says there is no Mother's Day caddis hatch on this river; a templated chart lists caddis as primary April-September (size 14-16).

Sources: Montana Angler, Montana Angler, Montana Angler, The Fly Fishing Place, The Fly Fishing Place, The Fly Fishing Place

Trico

Stage: spinner. Well sourced.

  1. Jan
  2. Feb
  3. Mar
  4. Apr
  5. May
  6. Jun
  7. Jul hatching
  8. Aug hatching
  9. Sep
  10. Oct
  11. Nov
  12. Dec

Peak: sunrise

Starts mid or late July. Emergence at sunrise, rarely lasting past a few hours; size 18-22.

Sources: Montana Angler, Montana Angler, Montana Angler

Scud

Single or templated source.

  1. Jan hatching
  2. Feb hatching
  3. Mar hatching
  4. Apr hatching
  5. May hatching
  6. Jun hatching
  7. Jul hatching
  8. Aug hatching
  9. Sep hatching
  10. Oct hatching
  11. Nov hatching
  12. Dec hatching

A crustacean, not a hatch. Size 14-18; a templated chart lists it as secondary in every month.

Sources: The Fly Fishing Place, The Fly Fishing Place, The Fly Fishing Place

Access, closures and rules change; check with the state agency before you go.