Henry’s Bugs: Opening Day at Harriman Ranch, Henry’s Fork, Idaho

I’ve turned over a lot of rocks in the knee-deep waters of the Henry’s Fork, the famous Snake River tributary that flows past Last Chance, Idaho. There are long stretches of time where there are no rising fish to be spotted, and my curiosity leads me to wonder what they are eating when they are not taking mayflies or caddis from the surface. Some guys like to nap on the bank. I look under rocks.

I’m always kind of shocked by how many leeches live in this river! Literally every stone I inspect has at least one, and sometimes as many as four squirming brown leeches attached. Do guys that are wet wading, bare legs unprotected by waders, have to pick the leeches off after each session? It’s plenty gross to think about.

The Ranch is known for big rainbows sipping mayflies, of course, so there are countless nymphs to try and identify. The green drakes were about to come off when I visited last year in mid-June, and there were plenty of fat, juicy, big-eyed nymphs around. I had just missed a hatch at one spot of the river, and there were hundreds of empty nymphal shucks floating by in the drift. Tying on a cripple pattern, intended to mimic a green drake that is stuck in its shuck, struggling to get free, fooled a couple of really nice fish. One of them got off as I pulled too hard and straightened out the hook, an event that seemed to happen to me a lot in 2021.

A pair of green drake nymphs, ready to pop out.

A green drake that I grabbed off the water’s surface as it struggled to escape from its shuck.

This cripple pattern came unbuttoned from a nice fish when the hook straightened.

Besides the flying bugs and squirmy leeches, I was a little amazed at the vast quantity of small scuds that were in every handful of weeds. Nobody fishes flies sub-surface at The Ranch, at least not many people admit to it, but there are plenty of fish that are gulping down non-winged bugs all day long.

A few olive colored scuds came up with this bit of weed, they are perhaps a size 20.

Another pair of lighter colored scuds, a hair bigger too.

One of the days that I was on the water there this past June, a fierce wind came up and blew whitecaps all across the wide slow water, ruling out any dry fly fishing, and I had a couple of miles to walk back to where I had parked the bike. Rather than get out and walk a beeline across the grassy valley floor, I changed up my dry fly rig to a bobber and a heavy red Copper John, which is about the size of the drake nymphs I’d been looking at.

Now, the section I was walking upstream through is very wide, very slow, and mostly featureless. So where do you think there may be a fish under the whitecaps, and where do you chuck your flies? Fortunately, the wind was at my back, so it was easy to cast with a water-haul, then let the wind take the flies upstream. I targeted any rock or log that broke the current, making a few casts to either side, and to my surprise, it worked!

This is likely a different fish, but you get the idea.

I think that day I got one nice fish on the Copper John and one on a big old Hare’s Ear. I didn’t have any small scud patterns to try, and I never got around to giving them a shot, because the salmon flies were popping up in Montana on the Madison, and I beat feet to get up there and try to get in on that hatch.

A Henry’s Fork salmon fly from earlier in June down by the Riverside campground.

But back on opening day at Harriman Ranch (June 15), the bugs that were getting it done were Pale Morning Duns in about a size 16 or 18. I had tied a variety of different style PMDs, but the winner seemed to be the ones with a natural goose biot body, a white CDC puff for a wing and a sparse grizzly hackle wrapped behind and ahead of the wing. The parachute style with a dubbed body were certainly easier to tie though.