I just got back to Idaho from a two week fishing trip to Japan where I experienced some spectacular fishing for Japan’s native trout the Yamame, the Jewel of Japan, and the Iwana, a Japanese char somewhat similar to our eastern Brook Trout. I had beautiful weather during my entire stay and this produced perfect fishing conditions. The incredible hospitality and generosity of my Japanese hosts made the whole visit one that I feel every fly fisherman should experience during their lifetime.
The entire Henry's Fork is fishing well at present. Here is an idea of what to expect on each stretch:
Box Canyon: For the most part the Box has been producing consistently good fishing. There has been a day or two over the past two weeks when for whatever reason the fish developed lock jaw but for the most part the fishing has been productive. Double nymph rigs dead drifted under an indicator have produced the best results. Fish a rubber leg nymph, size 10 or 12, with a small Zebra Midge, size 16 or 18, as your trailer. I suggest black or brown rubber legs with a brown, olive or purple Zebra Midge. There has also been some top water action with adult golden stone imitations. Try a Tubby Golden, HF Foam Golden Stone or Drowned Golden Stone and maybe drop one of those Zebra Midges off the dry fly.
The Ranch: After a bit of a slow start the Ranch water decided to wake up. We have PMD’s, Callibaetis, caddis of several varieties, Green Drake’s and Brown Drake’s all hatching right now. I can’t say one section is fishing any better than another. The fish seem to be spread out evenly throughout the entire Ranch. A few patterns we recommend to help you have a successful day on the Harriman State Park waters include Rusty Para-Spinners, PMD CDC Biot Duns, PMD Hybrid Sparkle Duns and PMD Short Wing Emergers, Callibaetis Para-Spinners and Last Chance Cripples, and tan and/or olive CDC Fertile and Bubbleback Caddis.
Warm River to Ashton: This section of the river has something for everyone. Dry flies, nymphs and streamers are all producing fish. For the dry fly enthusiast adult imitations of caddis, PMD’s, Golden Stones and Yellow Sallies are all getting the fish’s attention. A few fly recommendations include X-Caddis, EZ Caddis, PMD Tilt Wing Duns, PMD Improved Sparke Duns, Tubby Goldens, Drowned Golden Stones and yellow Stimulators. Double nymph rigs under an indicator are producing good results for the nymph fisherman. We like tan/brown and brown rubber legs, San Juan Worms, red, black, brown and purple Zebra Midges and Flashback Pheasant Tails for our nymphing. For the streamer fisherman we suggest flashy Kreelex and Sparkle Minnow streamers.
Ashton to Saint Anthony: Fishing down on this part of the river has gotten a little technical. There has been quite a bit of fishing pressure on this section and the fish are getting a little weary. There are still good hatches of Green Drakes, Golden Stones, PMD’s, caddis and Gray Drakes. In order to be consistently successful down here I recommend slowing down and spending more time watching the water and paying closer attention to each individual fish’s behavior. You are probably going to have to fish longer leaders with 5 and 6X tippets, be on your game with your casting and in most cases trim down your flies to a slimmer profile.