This river was discovered by white men in 1810 when a trappers' brigade led by Andrew Henry camped at Three Forks, where the Gallatin, Madison and Jefferson meet to form the Missouri, and were forced out by Blackfeet Indians. Henry led his brigade up the Madison, over Raynolds Pass near present Quake Lake Slide, past Henry's Lake and down along the river which was to bear his name. Henry was either the unluckiest or most incompetent trappers' brigade leader in history but the lake and river he discovered may just be the best trout stream and lake in the forty-eight lower states.
The lake, which is the source of the river, lies in a loop of the continental divide, which here is part of the wall of the Island Park Caldera, perhaps the largest collapsed volcanic caldera in the world. It is some twenty by thirty miles across, and the river meanders the entire length. The lake is fed by seven mostly snow- and rain-supplied creeks, and by icy springs in its bottom. It is very rich water for trout, loaded with weeds and insects. An idea of its quality may be gained from two facts: Trout of over 18 pounds have been caught there; and in the 1890s about 90,000 pounds of trout a year were harvested from the lake and sold commercially.
The river flowing from the outlet dam (which was put in in the early 1920s to raise the lake level for downstream irrigation) is just as rich as the lake. It winds across the grassy, often flower-blanketed meadows of Henry's Lake Flat, amongst the grazing cattle and sheep. This is a section of quiet runs and deep pools with often marshy or boggy banks and many spring-fed tributary creeks. The fish do not have many holding spots due to an almost featureless bottom, and tend to gather in the deeper pools. They are difficult to lure from these clear-water depths and are very much a stalking proposition. There are about six miles of this meadow-marsh water and then about two miles of dense willow swamp before the river meets the 480 million-gallon daily flow of 52 degree water from Big Springs.
From Big Springs confluence down to the U.S. Highway 191 bridge at Mack's Inn the river is a deep swamp-marsh stream of very large pools with a mostly silt-covered bottom. There is gravel underneath the silt, and it shows in some places, but in others the silt is deep enough to be very troublesome.
The land surrounding the stream here is all private; part of the Island Park Summer Home area, and of several fishing clubs. The status of the river has never been established as navigable, therefore one wants to be careful not to trespass. You will find the people friendly if you yourself are courteous and considerate of property rights.
It is six or eight miles downstream to the head of Island Park Reservoir. The distance varies with the lake level. This is riffle-and-run water for the most part. There is a short, steep canyon between Upper and Lower Coffee Pot rapids. This canyon is called Cardiac Canyon by some, but the true Cardiac Canyon is miles downstream at the upper-lower Mesa Falls area. At times there will be huge rainbows in the deep water of the canyon, at other times only smaller fish will be taken.
This upper section, from McRae's Bridge at the head of the reservoir to the section at Mack's Inn, is regularly stocked with hatchery catchable trout for the tourist trade. This has disturbed the wild trout; in some cases they have been forced by the sheer weight of numbers to retreat to the reservoir. But now and then you can find a pod of sizable wild fish in the deeps between Mack's Inn and the confluence of Big Springs, and in the Upper and Lower Coffee Pot sections.
Above the confluence of Big Springs and on to the lake outlet is all wild trout. This section is the least fished of any part of the river. This is largely because it is approached by roads only at the Highway 191 bridge just below the outlet and by the road that cuts left off Highway 191 (going south) just at the edge of Henry's Lake Flat, past Island Park Lodge.
This six-mile meadow section is one of the most beautiful areas in the world. Here one fishes alone in a pastoral meadow flat ten miles across, flanked on three sides by mountain ranges in excess of 10,000 feet, with wild animals, birds and waterfowl all around. In the clear air the mountains appear so close that one might toss a rock and hit them, yet there is a wonderful feeling of airy openness.
Fishing the dragonfly nymph here will produce only spotty success, though the fish run large, seldom less than two pounds. But the better fishing is with terrestrials: hoppers, ants, cricket and beetle patterns. One must seek concealment or kneel while casting and keep low until the fish are hooked. Though not much fished for, if at all, by human anglers, the trout are preyed on constantly by ospreys, eagles and herons. So they are wary. But they can be taken, and for the angler who hates crowds and loves solitude in lovely surroundings, Henry's Lake Flat is the place.
The long, deep section between the Big Springs confluence and Mack's Inn can and does produce good hatches and rises and generally fish over a pound. If one"can find an approach to the stream while avoiding trespass, this is truly excellent water. The hatches can be exasperating, for the silt bottom produces midge and blackfly by the millions and the trout feed lustily on these minute creatures. During these periods, which are the most common, a fly larger than size 20 is useless. Color or pattern is not important, but neutral colors do work best.
This section of the river has rainbow, some cutthroat and many small brookies during the summer. At Island Park Dam begins some twenty miles of the best fly-fishing for trout that can be found anywhere. The fish are in this stretch by the countless thousands and some will top twenty pounds. They are now all wild trout, no stocking is currently being done in this stretch and hasn't been for several years.
The spillway or tailrace of the dam feeds into the head of Box Canyon, the best fast-water stretch of trout fishing water in the country. There are about three miles of this fast, boulder-filled channel and pocket water and for the stouthearted angler it is a veritable cornucopia of riches and opportunities. The entire stretch is loaded with stone fly nymphs, at least three and perhaps five, species. There are a dozen species of caddis, several mayfly types, some crane fly larvae, and there are sculpins to fatten the huge, almost grossly fat rainbows that live here.
The canyon is entered most easily by the road turning into the reservoir just above (north of) Pond's Lodge, then turning off just short of the dam down to the boat launching spot about a half-mile downstream from the tailrace. Both up and down stream of this access point is good fishing for larger than average fish and this section is more easily waded than the rest of the canyon downstream of the tributary Buffalo, which enters just below the boat launching spot. Stone fly nymphs are the best choice of fly 80 percent of the time. Big floaters and terrestrials, or streamers-Dark Spruce, Marabou Muddier or a sculpin pattern-take care of the other 20 percent.
There are several entry spots below here, none easy. One comes from Highway 191 to the bank just below the juncture with the Buffalo River. Then this road (dirt) proceeds downstream along and back from the edge of the canyon, where turnoffs and parking spots appear several times in the next three miles. One parks, gathers up his gear, hoists his wader belt, takes a deep breath and clambers down into the canyon, about 300 vertical feet in most places.
Once into the canyon, your troubles just begin. Now, you have to find a spot where you can wade out far enough from the canyon wall to make any kind of a cast. Trees and smaller growth push right down to the water. In the edge of the water, and throughout, are boulders. Some are just ankle high, some knee high, some crotch high, and there are bigger ones and smaller ones passim. But it is the ankle- and knee-high rocks that cause the problem. All intent on your lawful occasions, you will turn to step here, or there, or move straight ahead, your foot will catch a slippery boulder in midstep, shoot off at the speed of light and hurl you headlong into the stream. You do not wade and fish. First, you wade. Then you fish. Then you wade some more. And fish some more. And so on. Try wading and fishing and you'll wind up wet, gasping for breath after an icy dunking or maybe being plastered against a huge boulder thirty feet downstream after being tumbled around like a twig.
The big stone fly nymph is the first choice of fly and used most of the time. Streamers and big floaters come into play when the nymph unaccountably doesn't work. And in early June, the dry imitation of the salmon fly can produce a bewildering number of sizes of trout. But in salmonfly time everything is crazy-the trout, the insect, the anglers, the weather, even the tourists.
Most of the canyon's three miles is very similar. Choice of location is by hunch, and usually one place is as good as the next. But the very mouth, where the water spills out from the walls of tumbled and broken rock and shoots down into the mile-long deep glide to Last Chance, is a special place.
The deep, channeled, rocky-bottomed glide curving from the mouth of the canyon down to beyond Last Chance is flanked by summer homes and is full of nice trout. It is mostly wadable and a joy to fish with either nymph or dry fly. In order not to trespass, most anglers move up the broken blacktop road along the river and stop at a parking area near the first of the streamside cabins. Then they wade across and go up the trail along the far bank to where they wish to fish. The mouth of the canyon can be reached by this trail. ^
The lower end of the Last Chance Run ends at the upper end of Harriman State Park, the famed Railroad Ranch. Something more than five miles of water is included in the Park but the water just above and below Osborne Bridge is not usually meant when fishermen speak of the Ranch. The Ranch water is as good as any trout water anywhere.
Almost any day from late May (fishing in Harriman Park does not open till June 15 as of 1982) through November there will be several species of flies on the water at the same time. Some of these will invariably be midge and blackfly. And the fish seen feeding may not all be taking the same insect, and some may be taking the emerging nymph or larvae and not the winged adult. This kind of thing is frequent and will drive you right out of your mind. Also, to add to your frustration, the larger fish seem to prefer the smaller flies.
Below Osborne Bridge on down to the little rural subdivision of Pinehaven, about three miles of water, there are some nice glides, a riffle or two, then the long, curving smooth-water stretch athwart Pinehaven. You will find private property signs on the trees and by the roads of the subdivision. Like any such zoned area, the land is private, the roads and streets public. And this is fortunate, for the half or three-quarters of a mile of water just above and below Pinehaven is a truly fine stretch of water with almost as many insects as the Ranch.
The trout are not as plentiful, but there are quite enough, and some exceed twenty-four inches. The place is seldom fished, though boats launched at Osborne Bridge do float through the stretch. Of an evening, the dry fly fishing can be unbeatable.
Below here is a section of broken water, riffles and runs, some glides and some almost-rapids, all the way to Riverside Campground, where our coverage ends. This varied water calls for varied fishing methods, wet fly, dry fly, nymph and streamer. It is perhaps best reached by floating and stopping to fish the likely or more appealing places, of which there are many. It is something more than ten miles by river from Osborne Bridge to Riverside, and if you do your work well and cover only the water that appeals to you, it is a very full day's fishing. It is varied and challenging and often very rewarding-and that's true of all of Henry's Fork.