The Henry’s Fork of the Snake River is one of Idaho’s premier trout streams. The “Fork”, as it is often referred to, is also one of the most beautiful and diverse rivers to be found anywhere. The “Fork” can also be one of the most challenging and frustrating rivers for the angler. Why?? Because it has one of the richest and most diverse populations of aquatic life forms found anywhere in a trout stream. Many times, while fishing the Fork, the angler will encounter more than one insect hatching at the same time. This condition is known as a multi‑masking complex hatch, and the angler must figure out what insect and what stage of the insect the trout are feeding on, and to make matters more challenging, this may vary from trout to trout.
In recent years certain sections of the Fork have become very prominent in fly fishing literature so much so that many anglers going to the Fork may find certain sections to be crowded. Therefore be tolerant of your fellow anglers or prospect around and fish some of the other sections. Because of the diversity of water found on the Fork, the angler who is willing to explore will find places where one doesn’t always have to match the hatch. Basically, there is water on the Fork for every skill level.
The most common mistakes made by anglers fishing the Fork are: poor presentation, poor approach, unreasonable expectations and the general lack of patience displayed by many anglers in working to an individual trout.
Poor Presentation: The angler wishing to fish the hatches on the Fork should spend some time practicing presentation skills. Because the trout, when feeding, will generally not move to take the offering, you must be able to put the imitation to the trout cast after cast.
Poor Approach: Many anglers give little or no thought to approach, but careful wading is a must on the Fork, or else many times you put your intended target down long before you are ready to make the first cast. Another thing, you don’t need to cast fifty or sixty feet to a trout. In actuality it’s really impossible to do so and achieve a drag free float due to the many and varied currents caused by the weed beds. Therefore, get as close as possible. Many times the angler can get within 20 feet of the trout if it is done by wading slowly, carefully and quietly.
Unreasonable Expectations: Fly - fishing for trout is not about “how many you caught” nor is it about “how big they were”. It’s more about the challenge between the angler and the trout and enjoying the beauty of the surroundings. Believe me, it is not a mortal sin if you don’t catch 30 trout!!! Why, I have had days on the Fork where all I have caught is a cold (from falling in) and two whitefish and even they were selective!!! But then again, I’m only a guide!!!
Angler Impatience: Pick a trout and stay with it. Just because the trout didn’t accept our first few casts doesn’t mean that the imitation won’t work. You may have been out of rhythm with the feeding cycle, or maybe there is some drag that you don’t realize. Wading around willy‑nilly and constantly changing flies, will get you lots of healthy exercise but few trout. Slow down and take your time.
THE LAKES AND RESERVOIRS
While visiting the Fork, don’t neglect Henry’s Lake or Island Park Reservoir. Both of these bodies of water offer some excellent fishing and many times the biggest trout of the trip can come out of these stillwaters.
All too often, while fishing, we forget to stop and “smell the roses” so to speak. While fishing the Henry’s Fork, remember to take time to stop and look around and enjoy this truly beautiful setting.
Good luck & enjoy!
| HATCH CHART FOR THE HENRY’S FORK | |||
|---|---|---|---|
| STONEFLIES | SIZE | AVAILABILITY DATES | |
| Salmon Fly | Pteronarcys californica | 2-6 | May 15-June 25 |
| Golden Stone | Calineuria californica | 4-8 | June 10-July 31 |
| Little Olive Stone | Alloperla signata | 12-16 | July 4-Aug. 10 |
| Yellow Sally Stone | Isoperla mormona | 14-16 | July 4-Aug. 15 |
| CADDIS | |||
| Grannom | Brachycentrus americanus | 10-14 | Apr. 1-May 25 |
| Spotted Sedge | Hyropsyche occidentalis | 10-16 | June 1-July 25 |
| Little Western Water Sedge | Amiocentrus | 16-20 | June 5-July 31 |
| Long Horn Sedge | Oecotie avara | 12-16 | June 1-July 21 |
| Little Sister Sedge | Cheumatopsyche campyla | 14-18 | June 10-July 31 |
| Speckled Sedge | Heliopsyche borealis | 16-20 | July 4-July 31 |
| Black Dancing Sedge | Myst. alafimbriata | 14-18 | July 10-Aug. 30 |
| Mottled Sedge | Neophylax rickeri | 8-12 | Sept. 1-Oct. 10 |
| MAYFLIES | |||
| Blue Winged Olive | Baetis tricaudatus | 18-22 | Mar. 5-Apr. 30; June 15-July 20 |
| Western Black Quill | Rhitrogena undulata | 12-14 | Apr. 1-June 1 |
| Brown Dun | Ameletus spartasus | 16-18 | May 15-June 15 |
| Pale Morning Dun | Ephemerella inermis | 16-20 | June 1-Aug. 25 |
| Western Green Drake | Drunella grandis | 10-12 | June 10-June 30 |
| Brown Drake | Ephemerella simulans | 12-16 | June 15-July 10 |
| Gray Drake | Siphlonurus occidentalis | 10-12 | June 15-July 10 |
| Slate Winged Olive | Ephemerella flavilinea | 14-16 | July 1-July 31 |
| Speckled Spinner | Callibaetis nigritus | 14-18 | July 5-Sept. 15 |
| Trico | Tricorythodes minutus | 18-22 | Aug. 1-Sept. 30 |
| Tiny Blue Winged Olive | Pseudocleon edmundis | 20-24 | Aug. 10-Oct. 20 |
| Black Quill | Paraleptophlebia heteronea | 16-18 | July 10-Aug. 20 |
| Mahogany Dun | Paraleptophlebia bicornuta | 14-18 | Sept. 1-Oct. 25 |
| Slate/Cream Dun | Epeorus albertae | 14-16 | July 1-July 31 |
| White Mayfly Dun | Ephoron album | 12-16 | Oct. 15-Oct. 30 |
| TERRESTRIALS | |||
| Black Ant | Formicidae | 14-22 | Apr. 15-Sept. 30 |
| Cinnamon Ant | Formicidae | 14-20 | Apr. 15-Sept. 30 |
| Black Beetle | Coleoptera | 10-20 | June 15-Sept. 15 |
| Grasshoppers | Acrididae | 4-14 | July 10-Sept. 30 |
| Pine Bark Beetle | 14-20 | June 20-Aug. 20 | |
| Green Leafhopper | 18-22 | July 10-Sept. 10 | |
| Brown Flying Ant (Termite) | 12-16 | Aug. 1-Sept. 10 | |
| Black Flying Ant | 14-20 | Aug. 10-Sept. 10 | |
| MIDGE | Diptera | 16-24 | Available All Year |
| AQUATIC FOOD FORMS | |||
| Snails | Gastropoda | 10-14 | July 1-Sept. 30 |
| Damsel Fly Nymphs | Zygoptera | 10-16 | May 10-Aug. 15 |
| Fish Eggs | Assorted Species | 10-16 | Throughout Various Spawns |
| Water Beetle | Heteroptera | 10-16 | May 1-Sept. 1 |
| Dragon Fly Nymph | Odonata | 8-12 | May 10-Aug. 15 |
| Free Swimming Caddis Worm | 10-16 | Available All Year | |
| Cased Caddis Nymph | 8-16 | Available All Year | |
| Assorted Stonefly Nymphs | 2-16 | Available All Year | |
| Assorted Mayfly Nymphs | 8-22 | Available All Year | |
| Midge Worms | 14-20 | Available All Year | |
| Leeches | Hirudinea | 4-16 | Available All Year |
| Whitefish Minnow | Prosopium williamsoni | 4-8 | Available All Year |
| Backswimmers | Heteroptera | 12-20 | Available All Year |
| Sculpins | Cottidea | 2-8 | May 1-Sept. 15 |
| Kokanee Salmon Minnow | 2-10 | Available All Year | |
| Crayfish Minnow (Island Park Res.) | 2-10 | Available All Year | |
| Dace Minnow | 4-10 | Available All Year | |
| Scud | Hyalleia azteca | 8-16 | Available All Year |
| Chub Minnow (Island Park Res.) | 2-8 | Available All Year | |
Originally published November 9, 2009 on Fly Anglers Online by Tom Travis.