Swan Valley's Bear Creek, An Idyllic Mountain Stream

IRWIN — Grasshoppers buzzed and flitted from my path as my old dog Spooner and I trudged up the Bear Creek trail on a warm July day. The bugs were a welcome presence considering the cache of terrestrials I tied up the night before in preparation for Bear Creek’s feisty cutthroats.

The trail is no sweat, even for the novice hiker and even laden with the grasshoppers and mounds of acrid horse droppings. I’ve always been of the mind that I can walk anywhere — even if I have to step over a
Bear Creek is the idyllic mountain stream that meanders through an equally serene alpine valley on the south side of Palisades Reservoir.
Photo by Chris Hunt

few road apples — as long as there are fish waiting at the destination, And, as trails go, the path along Bear Creek is one that can easily be undertaken in a pair of sturdy wading boots — you don’t have to walk very far or very long to get into some good fly fishing, and there’s not much on the trail will really test your footing

Bear Creek, the idyllic mountain stream that meanders through an equally serene alpine valley on the south side of Palisades Reservoir, is a pleasant fly fishing destination and home to some pretty eager Snake River cutthroats that rise often to big hopper and black ant patterns. And on this day, Old Spoon and I were in search of Bear Creek’s cutthroats.

About 30 minutes after we started walking (I told you it wasn’t much of a hike), I had a size 12 Joe’s Hopper tied on and was casting upstream to a fishy-looking riffle. Spooner, as he always does watch the first few casts to see if I'd have any luck.

If I get into fish immediately, he hangs around to watch. If things are a bit slow, he’ll wander off into the willows and look for a cool spot to take a nap.

On just my first cast, a pan-sized cutthroat rolled over the hopper and took off on a downstream run. Stripping line in quickly to keep up with the fish’s retreat, I was able to land the little mountain jewel without putting too much stress on it — an important consideration with water temperatures at their peak in late July. The cutthroat, about 10 inches long, positively glimmered in the afternoon sun; the telltale red gash was deep and brilliant beneath its gills. Its tail was dotted with hundreds of small black dots, a marked difference when compared to its close relative, the Yellowstone cutthroat, which sports larger, less dense dots on its tail and body. I quickly released the fish and started in search of my next victim.

Spooner, as it turned out, hung around most of the afternoon.

Prime water

From the trailhead at Bear Creek, the best water is about a 30-minute hike upstream. Simply follow the easy trail upstream for about half an hour and then start fishing. Along your way, you’ll see plenty of inviting water, and if you can’t resist, give it a shot. But I’m telling you now, the stream’s bigger fish — the resident trout that live in Bear Creek all year long — make their home in the creek’s upper reaches.

It’s possible to fish the stream right at the trailhead, but I’ve never had much luck with larger trout there — I’ve caught plenty of little ones, though.

As you hike upstream, keep an eye out for beaver activity. If you come across a beaver pond, don’t hesitate to give it a try — the dams slow the water and provide great habitat for insects. As a result, the cutthroats will gather there and grow a bit bigger.

Don’t be discouraged by the stream’s cloudy appearance. While it will run mostly clear by mid-summer, it quickly dusts up after a storm and never really runs perfectly transparent like other streams in the area. At its best, the water runs out of the mountains with an inviting green tinge to it. And watch your footing while you wade — a thin layer of silt almost always covers the streambed’s rocks, and if you’re not careful, you’ll end up good and wet.

The fish

Bear Creek’s cutthroats aren’t large — you’ll probably catch more six- or eight-inch fish than anything else. But there’s hope in this stream — every now and then you’ll latch on to a 12-inch mauler that will test light tackle and really put on a show. I’ve never caught big cutthroats on Bear Creek, just lots of them.

To get into the stream’s bigger fish, it’s best to show up early in the season — by the middle of June, I’ve found that most of the fish that ran up the creek to spawn are on their way back to Palisades Reservoir, where they make their home the rest of the year. And, in low water years, the fish may never even make the run at all, choosing to remain in the reservoir rather than deal with warming water temperatures.

The real treasures of Bear Creek are the aggressive resident fish who have forsaken life in the lake for a spartan existence in the stream. They don’t get very big, but a 12-inch cutthroat hooked in heavy cover can provide plenty of challenge for the fisherman armed with light tackle.

In the fall, it’s also possible to catch brown trout. A few of Palisades’ resident browns use the stream as a spawning ground, but it’s rare to hook into a bronzeback, even when they’re in the stream.

The flies

Early in the year, approach Bear Creek with really basic patterns. The stream environment, while not sterile, isn’t nearly as productive as that of nearby Palisades Reservoir, so a flashy attractor pattern like a Royal Coachman or a Yellow Humpy will usually draw plenty of strikes. Later in the season, say from the middle of July on, the fish dine on a buffet of terrestrial bugs — grasshoppers, crickets, ants and beetles. Arm yourself with some good terrestrial patterns, size 12 to 14, and you won’t be disappointed. Also, with these big patterns, your chances of latching on to one of the streams bigger fish are pretty good.

How to get there

Take U.S. Highway 26 east of Idaho Falls and follow it to Irwin. Take a right at Palisades Dam, drive across the dam and follow the signs to the Bear Creek trailhead on a serviceable dirt road maintained by the Forest Service.