Fall River hatch chart providing fly subspecies, sizes and emergence dates for major mayfly, caddisfly, stonefly and midge hatches occurring annually on the Fall River in eastern Idaho.
Hatch sizes and activity dates for Fall River hatches may fluctuate from year to year due to changes in water flows and weather conditions. For anglers fishing the Fall River, having a selection of fly patterns covering the major hatches is recommended.
| Fly Hatch | Size | Date |
|---|---|---|
| Midge | 18 - 22 | Jan 1 - Apr 30; Sep 1 - Dec 31 |
| Pale Morning Dun | 16 - 20 | June 1 - July 31 |
| Green Drake | 10 - 14 | June 1 - July 31 |
| Salmonfly | 4 - 6 | June 1 - July 31 |
| Golden Stonefly | 8 - 12 | June 1 - July 31 |
| Caddis | 14 - 16 | June 1 - Aug 31 |
| Spruce Moth | 10 - 12 | July 1 - July 31 |
| Terrestrials | 6 - 18 | July 1 - Oct 31 |
| Trico | 18 - 22 | Aug 1 - Oct 31 |
| Mohagany Dun | 16 - 18 | Sep 1 - Oct 31 |
| Blue Winged Olive (Baetis) | 16 - 24 | Sep 1 - Nov 30 |
| Fall (October) Caddis | 8 - 12 | Sep 1 - Nov 30 |
Fall River Fly Patterns
Fishing adult stonefly patterns and nymphing subsurface with patterns that match the hatch is your best bet for netting some decent size trout on Fall River.
Terrestrials, especially grasshopper or attractor patterns will hook some larger trout during the summer months and well into the fall.
One specific fly pattern anglers report having success with is a #8 Coffee Black Pat’s Rubber Legs on a dropper. A Pat’s Rubber legs is a great imitation for a stonefly nymph and stoneflies are one of the more prolific hatches on Fall River during the spring and summer.
