Idaho High Lakes Best in Fall
Avoiding heat in the valleys by fishing Idaho’s high elevation lakes in summer is an honored tradition but the fishing is actually best in autumn. Be prepared for tricky weather. This article is adapted from Idaho Outdoor Digest.

A hatch of small caddis flies fluttering across the water, attracted the hungry brook trout. The small dry fly bobbing amid the real insects hadn’t been ignored for more than a few minutes all afternoon.

Each take was fast. A flash of white was followed by a swirl on the surface of the water. Raising the rod sharply brought the line tight and drove the fine wire hook into another trout’s jaw.

The fish were small, but each put up a scrappy fight until being pulled close enough that the barbless fly could be removed and the trout released.

Even now, resting on the ridge trail and looking back down at the lake, I kept recalling the afternoon’s fishing. Casting flies to the trout dimpling the surface of the crystal clear water was just a part of the beauty of the lake.

The evening sun had turned the high mountain lake into an azure jewel set on a green velvet cloth of evergreen forest in the distance. Bright red and purple patches of huckleberry brush adorned the open slopes to either side. Colorful maple and mountain ash highlighted the draws.

The whole scene, even the bright spots on the brook trout and the last aster blossoms, had been rendered more intense by the soft autumn sunlight. It was a perfect day for filling the mind with Idaho mountain memories.

The distance between us, resting on the ridge trail, and the lake, nestled into the back of a glacial basin, was short as the raven glides. The trail, however, traversed swampy downed timber, skirted a few cliffs and then switch-backed up through head-high snowberry brush.

The climb had already taken over an hour. With the October sun only five fingers above the horizon, we had to cut short our lazy savoring of the fall colors and mountain scenery. It was already past time to start on down to the car, four long trail miles away.

good trout from Idaho high mountain lake

Some Idaho high mountain lakes yield sizable trout. This lake lies at the top of the Sawtooths.

Fishing at least on high mountain lakes is a must on my outdoor schedule every fall. In the Idaho Panhandle, my favorite time for high lake fishing is October.

Oh, I’ve got nothing against high lakes in June or July, because the fish just go crazy after the ice goes off. High lakes trout gobble up practically anything then, and do it with enthusiasm.

By mid-summer, though, even high mountain lakes have their dog days. The easy angling of ice-out springtime on the high country lakes is past then.

The half-starved trout that gulped down any offering the first few weeks of their short summer are gorged with insects and inclined to be picky eaters by mid-August.

Trout of the high lakes, whether they are native cutthroat or introduced brookies, or even rainbow or goldens, will turn up their colorful noses in late summer at fat angleworms and carefully cured salmon eggs. Those fish will follow and then refuse, all manner of spinners and lures.

Then comes the crowning insult. An obviously overfed trout rises with splashy insolence to some practically invisible insect right at your feet!

The high lake trout may only be feeding in splurges a half hour long at summers’ peak, but all that changes with the first frosts of fall. By October insect life in Idaho’s high lakes is on the wane for another year.

Fly Fishing Perfect for Fall

What insects are around tend to be blown onto the water from shoreline grass and trees. The fish cruise hungrily much of the day, perfect targets for flies cast from the bank.

In the Idaho Panhandle north of Sandpoint, where I’ve done my fall fishing in the high country, anglers have two entirely different kinds of mountain lakes to choose from. In the Cabinet Mountains back of Clark Fork a handful of lakes are full of brookies, stocked so long ago no one knows for sure who put them there.

In the Selkirk Mountains, which stretch from Sandpoint’s city limits north, well up into Canada, are more lakes, most holding rainbow or cutthroat trout. A one-time stocking of golden trout in one of the Selkirk Lakes apparently never took hold.

The Selkirk lakes all rest in granite hollows, carved out by glaciers and left behind by the last ice age. In the Cabinets, much older, shelving bedrock has been scoured by other glaciers to create depressions where water collects deep enough to support fish all year long.

The trail we were heading down left one of the small Cabinet Mountain lakes behind. The southern shore of that particular lake has a lot of shallow water and a reedy margin.

The swampy ground back of the shoreline is open, making that part of the lake a great place to cast a dry fly. Anglers armed with spinning outfits and clear plastic bubbles can do the same thing along the steep, tree-lined north shore of the lake.

Most of the best high mountain fishing lakes are reached only with some hiking effort but the rewards in scenery and angling experiences can make them worthy of the walk.

Which tackle you use is a matter of preference. I suspect the spinning gear is most effective but I’m firmly anchored in my fly rod habit and it produces enough fish to keep me happy.

Light leader does make a big difference, for at least a foot or two back from the fly, no matter what tackle you use to fish high lakes. On a sunny day even a fine line can cast a shadow as wide as a heavy rope in the crystal clear water of a high lake.

Flies that mimic beetles or caddis flies are good choices for most mountain lakes. For an all-purpose fly, a number 14 or 16 Renegade, or an Adams that size, is tough to beat.

Just in case the fish won’t hit on top I always take along a few small nymph patterns. Some dark nymphs, like a hare’s ear or zug bug or Tellico nymph, are great in size 12 or smaller. A Carey Special makes a good attractor pattern, and a size four or six is not too large if you can fish it close to the bottom.

I don’t worry much about using tiny midge and mosquito larvae patterns on high lakes this time of year. For me they just don’t provoke the savage strikes that I think make lake fishing so exciting.

Though the scenery is different, high mountain lakes I have fished in south-central Idaho have the same virtues as those in the Panhandle. From other fishermen I’ve talked to, so do the high lakes in the central Idaho wilderness, and the McCall area, and the Seven Devils country.

Each Lake is Unique

Each lake is unique, of course, and the more you visit one the more you get to be friends with it and really know the place. You learn if a lake has enough spring flow to keep big fish alive during a bad year when the ice stays on too long.

You learn whether the ice goes off early or late, and whether the water is shallow and warms up in sunny weather. You learn what kind of weather makes the lake a great place to visit, and in what sort of weather to stay home.

Mountain lakes are scattered throughout Idaho, stretching from Hidden Lake in the Selkirks, only about 10 miles south of the Canadian border, to Lake Cleveland on Mount Harrison south of Burley.

In between there are over l,850 more high country lakes. I don’t know if it’s unfortunate or not that there’s no comprehensive guide to those high lakes. Most high lakes aren’t overused.

On the other hand, by their nature high lakes are features of a fragile landscape. Cabins built by prospectors a hundred years ago haven’t rotted away yet in that high country. It’s no surprise, since life there is frozen to a stand still more than half of each year.

The charred embers of a campfire or the trash of a careless camp may be visible around a high lake even after the campers who left those scars are no longer among the living. The pace at which nature covers man’s tracks is painfully slow in the high country.

That doesn’t mean you should stay out of the high mountains. Far from it! The slow movement of growth and decay among the mountain peaks makes for a part of Idaho that’s totally unique.

There is a responsibility, though, that high country visitors should accept. That is to respect and protect the fragile nature of a mountain lake’s beauty.

Whether you like a chance of catching a trophy trout, or prefer pan-sized fish will have a lot to do with which high mountain lake you head for.

Little Brookies and Lunkers

Eastern brook trout are prolific shoreline spawners. Because of the relatively light fishing pressure on most high lakes, that means the brookies will over-populate the water in time and “stunt out.”

A lake full of stunted brook trout will include old spawners no more than five or six inches long. Those fish are not trophies, by any means, but they can make for lively action. In my opinion, they’re also as good eating as any trout in Idaho. They’re at their bes if you can get them into the frying pan right on the lake shore.

Even in a lake full of little brookies, there may be lunkers. What I think is the prettiest high lake in the Cabinet Mountains is well-known for its stunted brook trout. The biggest fish I ever caught from that lake couldn’t be stretched to eight inches long, and I’ve caught a couple hundred brookies there.

A Sandpoint machinist didn’t know there are only little fish in the lake, so he trudged up the trail packing some stout tackle and heavy spinners. I thought that was ridiculous until he showed me a photo of a genuine trophy brook trout from the lake. The fish he had caught was heavy-bodied and weighed over two pounds!

High lakes holding rainbow and cutthroat, though, especially where the fish can’t reproduce successfully and their numbers are controlled by careful stocking, are more consistent places to find big trout.

By big I mean in the two-pound range. Trout much larger than that can survive a winter under the ice in only a handful of Idaho’s high mountain lakes.

Prepare for Possible Weather

If you’re heading into the high country now, don’t forget to take along at least a waterproof windbreaker and a warm sweater. There will probably be frost early in the morning and the extra clothes will feel good. You will also want all the gear you can get if it showers. When it comes with a strong breeze, even a brief rain can be dangerously chilling.

Not that rain is all that likely. October can have some of Idaho’s finest weather. The breeze we fished in all day was barely strong enough to carry along the seed fluff from the matured fireweed blossoms. In that kind of weather it’s nice to be able to put the sweater and jacket in a day pack until they’re needed.

The only problem with fishing mountain lakes in the fall is the time it takes away from all the other things there are to do outdoors now. There’s good bass and trout fishing on lowland waters. Big game seasons are also opening, not to mention the hunting for grouse and ducks and geese and pheasants and partridge.

If you’re in love, though, as I am, with the crisp smell of high country air and clear views of mountain scenery, picking high lake fishing from October’s outdoor smorgasboard still isn’t a difficult choice.

Dave Finkelnburg was educated as an engineer, a profession to which he has returned after years of outdoor writing and editing for North Idaho newspapers and magazines when he is not hunting and fishing throughout Idaho. He lives in Pocatello.