Fall Baetis 101

Pack your small fly box and slay

Two days ago I was driving from Montana’s Bitterroot Valley to the Madison Valley and along the way I passed the upper Big Hole River near Wisdom. That’s one of the coldest areas in the state and frequently finds itself listed on the national news for the top low temperature in the country.

While that distinction means a lot of people around there probably hate the first few cool days of the fall season (meaning they know that winter is near), it also means that anglers can take advantage of afternoon Baetis hatches that provide awesome drly fly opportunity. That’s what I did; I had my two daughters with me but I rolled down their windows, stepped to the side of the highway and let them cheerlead. I caught four brook trout on small dries and a whitefish and, a bonus, a 15-inch grayling all with “nice job dad” ringing out of the pickup. Sweet!  At one point, Tate, who recently visited Alaska with me, said, “Dad, I hope you catch a big silver.” I didn’t have the heart to tell her that the Big Hole, eventually, drains into the Gulf of Mexico.

That fall Baetis action isn’t restricted to the upper Big Hole. Shortly, you’ll find Baetis on most western waters including some of my favorites—Idaho’s South Fork Boise, Henry’s Fork, Silver Creek and North Fork Clearwater; Montana’s Bitterroot, Big Spring Creek and upper Madison; and Wyoming’s Firehole River, Flat Creek, Green River, Tongue River and Salt River, among many others.

Here’s how to approach a fall Baetis day. First, watch the weather. If it’s overcast and spitting a little rain or snow, so much the better. Bright overcast days typically aren’t banner. Expect to get cold fishing fall Baetis—that’s the deal. Pansy-ass, skirt-wearing, tea-sippin’ whiners need not apply. If you decide your game then show up with your fleece and watch the water closely between 11 a.m. and 6 p.m. Given overcast conditions you could see the start of an emergence around 11 or noon, a peak in activity between one and five, and a windup around six.

You don’t have to throw nymphs during this fray. Instead, pack size-16, 18 and 20 gray or olive Sparkle Duns, Baetis cripples and Parachute Adams. Fish those dead-drift, with no drag, off nine-foot 5X tippet or even 6X depending on how leader shy and large the fish are. If they are big trout stick with the 5X and offer downstream presentations so that they never see your leader. With less educated trout you can cast a tippet over their heads and it shouldn’t bother them.

If you arrive prior to the hatch or you want to fish after the true hatch, try Flashback Pheasant Tail Nymphs and gray Hare’s Ears, size-16, 18 and 20. Fish those off 5X and under a small indicator. Fall Baetis mostly come off on slow-moving sections of water, meaning slicks, tailouts and such. You don’t want to throw an oversized indicator or you’ll send trout flying for cover.

Cool. The fall Baetis hatch is pretty straightforward and even novice anglers enjoy great success with it. Pick your fish. Make great casts. Keep your fly floating without drag. And fight those fish gingerly on light tippet. You’ll have a blast…as long as you man-up to the weather.

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