armstrong-spring-creek

Armstrong Spring Creek is a creek in Montana.

It ranks #11 among the 17 waters of Montana in the registry, and is of national prominence.

Also called Armstrong's, Armstrong's Spring Creek, O'Hair Spring Creek and Armstong's Spring Creek.

Fished for trout (inferred from the species listed).

Species: rainbow trout, brown trout, cutthroat trout, cutbow and mountain whitefish.

No GNIS feature exists for this water. It is a private spring creek on the ranch channels near Livingston, Park County, Montana, and the USGS gazetteer does not record it. Same-named GNIS features (Armstrong Creek in Carbon County, Depuy Creek in Flathead County) are DIFFERENT streams and must never be bound to it.

Rod fee required — book with the owner. Booking and owner details. Rod fee with advance booking; rate varies by season. Not yet verified. Rod fee and advance booking; private land, publicly bookable.

Lower Armstrong's (stretch). Rod fee required — book with the owner.

Middle Section (stretch). Rod fee required — book with the owner.

Upper Armstrong's (stretch). Rod fee required — book with the owner.

Diagonal Riffle (hole). Rod fee required — book with the owner. Booking and owner details. Inherited from parent water: Rod fee and advance booking; private land, publicly bookable. Also called The Diagonal.

It is on the stretch Middle Section.

It is downstream of Number 2 Riffle.

Number 2 Riffle (hole). Rod fee required — book with the owner. Booking and owner details. Inherited from parent water: Rod fee and advance booking; private land, publicly bookable. Also called #2 Riffle.

It is on the stretch Middle Section.

It is upstream of Diagonal Riffle.

It is downstream of Big Rock Section.

Big Rock Section (hole). Rod fee required — book with the owner. Booking and owner details. Inherited from parent water: Rod fee and advance booking; private land, publicly bookable.

It is on the stretch Middle Section.

It is upstream of Number 2 Riffle.

It is downstream of Corral Area.

Corral Area (feature). Rod fee required — book with the owner. Booking and owner details. Inherited from parent water: Rod fee and advance booking; private land, publicly bookable.

It is on the stretch Middle Section.

It is upstream of Big Rock Section.

DePuy's Border (feature). Rod fee required — book with the owner. Booking and owner details. Inherited from parent water: Rod fee and advance booking; private land, publicly bookable.

Sourced from 3 independent fly sites.

Sources: Montana Angler, outsidebozeman.com, parksflyshop.com, yellowstoneangler.com (retrieved 2026-10-20), yellowstoneangler.com (2) (retrieved 2026-10-20) and yellowstoneangler.com (3).

Hatches

Baetis (spring)

Stage: nymph, dun. Well sourced.

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

Peak: mid-to-late March

Nymphs from late February; fish key in mid to late March; hatches continue to the end of April. Best when air is above 50F, cloudy and calm. Size about 18-20.

Sources: yellowstoneangler.com, yellowstoneangler.com

Mother's Day Caddis

Stage: emerger, 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
  7. Jul
  8. Aug
  9. Sep
  10. Oct
  11. Nov
  12. Dec

Reported windows differ: late April on one page, late April and early May on another. Splashy rises to emergers; Brachycentrus occidentalis.

Sources: yellowstoneangler.com, yellowstoneangler.com

Sulphur (small summer baetis)

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

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

Late-afternoon duns about 4-6 PM; size 20-24 on one page, 20-22 on another. Nymphs fished late July to early September; continues into August after the PMDs stop.

Sources: yellowstoneangler.com, yellowstoneangler.com

Damselfly

Stage: nymph, adult. Well sourced.

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

Nymphs year-round; dries best in summer; mostly ponds.

Sources: yellowstoneangler.com

Terrestrials

Stage: adult. Well sourced.

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

Ants, beetles, hoppers and crickets.

Sources: yellowstoneangler.com

Pale Morning Dun (Ephemerella infrequens) (Ephemerella infrequens)

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

  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

Reported sizes differ: 14-16 on one page, 14-18 on another. Larger first PMD; emerges mid-June to early July, and mid-June to mid-July is the best dry-fly period. Duns mid-morning; spinners evening, sometimes morning. Timing also stated as late June to early July.

Sources: yellowstoneangler.com, yellowstoneangler.com

Baetis (fall)

Stage: dun. Well sourced.

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

Often windy.

Sources: yellowstoneangler.com, yellowstoneangler.com

Pale Morning Dun (Ephemerella inermis) (Ephemerella inermis)

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

  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

Reported sizes differ: 18-20 on one page, 16-20 on another. Smaller second PMD; mid-July through August; fish emergers.

Sources: yellowstoneangler.com, yellowstoneangler.com

Callibaetis

Well sourced.

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

Mostly on Dick's pond and the upper pond; size 14-16.

Sources: yellowstoneangler.com

Also named, timing not yet researched: Midge.

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