‘River X’: The best trout stream within 100 miles of Big Sky

By Patrick Straub EBS Fishing Columnist

In this age of social media with its instant gratification—if a salmon fly hatches at 8 a.m. on the Upper Madison River, the news of its hatching is on Instagram at 8:05 a.m.—much of the mystery has been taken out of fly fishing.

I recognize the desire to broadcast exciting things, I really do. I understand the satisfaction to share one’s experiences. And I see the positive impact of social media, because I own a fly-fishing business that relies on providing up-to-date, accurate information.

Yet with all of the immediate access to knowledge, and the importance placed on sharing rather than actually going, what has become of fly-fishing secrets? I’m talking about the tidbits of knowledge that were gained by earning an old-timer’s trust, eavesdropping at the local bar, or just plain trial-and-error of time spent on the water. So, here’s a profile on the best river in the best fly-fishing corner of the entire world.

“River X” originates from the snow that falls in the mountains in and around Yellowstone National Park. Near its headwaters are pristine meadows teeming with wildlife and native grasses. In winter this is a cold and desolate place, but the deep snows of winter allow for abundant summer streamflows.

Beginning in March it’s possible to fish dry flies to rising trout. Just after runoff some of the river’s largest trout are caught on salmon flies. Caddis and PMDs hatch in summer and great terrestrial fishing begins in earnest by August. For anglers who like technical dry-fly fishing, come here in late fall and headhunt rising trout sipping late-season mayflies.

Did I mention the streamer fishing? The fall streamer fishing can be quite good, with plenty of large fish to be taken by stripping or dead-drifting streamers, while wade fishing or dragging flies from the boat. River X’s lower reaches fish well early and late in the season, and some of the year’s largest brown trout come from the lower river while float fishing.

Solitude can happen on River X as well, for those anglers willing to cover some ground on foot, especially in the upper sections of the river during certain times of the year. Prepare for tricky wading as steep banks, deep runs and large boulders create wading conditions not suited for all abilities—but the effort usually pays off with some exciting fishing on the area’s greatest trout river.

River X has sections that are fast and others that are slow. In the fast water you’ll need to mend quickly and get a good, but short drift. In the slower sections, your drifts will need to be long and drag-free. Learn a reach cast. Perfect your double-haul so you can cover more water with a dry fly or a streamer. And it’s always a good idea to perfect your knot-tying so that you can spend more time fishing and less time tying.

The best flies for River X are Pat’s Rubberlegs in coffee and black, sizes 8 and 10; Parachute Adams in size 12 and 18; Parachute Caddis in size 14 and 16; and your favorite streamer patterns. Be sure to have plenty of leaders in a wide range of sizes, but have ample 9-foot and 7.5-foot 3X and 4X leaders. For nymphing, use fluorocarbon tippet, and a strike indicator to ensure more hook-ups.

If you plan to use a boat to fish River X, being experienced on the oars is a must for success and safety. Some sections of River X are very dangerous to float at certain levels. Rafts and drift boats all work to float the various sections of River X, but in lower water conditions or on certain sections a raft might be more versatile, but less comfortable. Although River X’s abundant trout can be caught on foot, using a boat allows you to cover more water.

So what is the true identity of River X? You won’t find the answer in a tweet, or a post or a feed. You’ll have to go and find out for yourself. And, in doing so, you’ll find your own River X. What you choose to do from that point is up to you, and your followers, friends or likes.

Pat Straub is a 20-year veteran guide on Montana’s waters and has fished the world-over. The co-founder of the Montana Fishing Guide School, he’s the author of six books, including “The Frugal Fly Fisher,” “Montana On The Fly,” and “Everything You Always Wanted to Know About Fly Fishing.” He and his wife own Gallatin River Guides in Big Sky.