Most of Montana's rivers are too high and muddy to fish right now.
And I doubt many have crested yet. It's just now starting get
warm, and there's a ton of snow left up in the mountains yet.

I hiked up the Beartrap Canyon of the Madison Saturday. Left
early, to get out ahead of the unwashed masses. My buddy
Steve and I started off dead drifting sculpins and crayfish
near the bank. The water was high and off color, and that's what
the flyshop said to do. But that didn't work out well.

I eventually switched to a big, heavily weighted open-cell foam
stonefly nymph (a Marshmallow Nymph) followed by a big #10 bead-belly
hair hackle wet fly--what I now like to call a Pott Sticker.
They're my easier-to-tie takeoffs on Franz Pott's most famous
fly, the Sandy Mite.

I absolutely wacked'em. I don't know you you explain it.
Outside of a hatch, I've never seen a simply fly change make
such a difference. I tried fishing the Hair Hackle alone for
a while and didn't do so well. I put the Marshmallow Nymph
back on and wack. There they were. But the funny thing was
they all took the Hair Hackle. The big nymph needed to be
there, it seemed. Maybe it got their attention. But it was
the Hair Hackle they ate.

http://montana-riverboats.com/pottstickers.php