Harriman State Park / Falls Areaon Henry's Fork of the Snake River
River flow last 30 days
Strong Blue-Winged Olive (BWO) hatches
- 01Strong Blue-Winged Olive (BWO) hatches, especially on overcast afternoons.
- 02Consistent Mahogany Dun and October Caddis activity providing dry fly opportunities.
- 03Midges and Speckled Spinners remain a year-round staple.
- 04Focus on slower, meandering sections, Harriman Ranch, and Ashton to Funny Farm stretch.
- 05Pay close attention to rise forms; use delicate dry flies/emergers for risers and dry-dropper rigs in faster water.
What to tie on at Harriman State Park / Falls Area
Picked from recent reports for this stretch.
Blue-Winged Olive Comparadun
BWOs are actively hatching in the fall, especially on overcast days, and this low-profile dry fly is excellent for selective trout.
Buy at AmazonPine Squirrel Leech (Olive)
Small leech patterns like this effectively mimic sluggish baitfish and annelids in cold water, triggering strikes from larger, lethargic trout in the fall on the Henry's Fork.
Flashback Pheasant Tail
An excellent general searching nymph, mimicking various aquatic insects active subsurface year-round, and particularly effective in fall conditions on the Henry's Fork.
Copper John
A versatile attractor nymph, effective year-round in faster water, ideal for prospecting deeper runs where fish are holding in cooler fall temperatures on the Henry's Fork.
Buy at AmazonZebra Midge
A staple winter tailwater pattern that perfectly imitates midge pupae. Red or black colors in sizes 20-22 are most effective on the Henry's Fork right now.
Buy at AmazonSow Bug
The Henry's Fork has massive populations of aquatic isopods. These are a constant, high-protein food source available to trout throughout the winter months.
Buy at AmazonRS2
An exceptional midge/baetis emerger pattern that is deadly when fished as a trailing nymph or just under the surface film during active midge hatches.
Jujubaetis
Baetis nymphs are a year-round food source, and this pattern is highly effective for imitating them, especially during consistent BWO activity.
Buy at AmazonMayer's Mini Leech
Small leech patterns effectively mimic sluggish baitfish and annelids in cold water, enticing strikes from larger, lethargic trout in early spring conditions.
Idaho season by season
What changes on the water through the year, with the flies for each season.
Fly shops nearby
Local flies, current advice and guided trips.