I favor small streams over big streams - they are much easier to navigate and cross, the trout are concentrated in deep runs and usually the banks are "butt high" for an easy sit down to relax, and they usually run through pastures that mean grasshoppers and attractor flies!!
The above stream is running high with irrigation water for downstream ranchers. Soon the flow will be reduced as the irrigation needs cease as fall approaches and the trout concentrate in deep banks and corners.
This big boy came from a similar corner 3 years ago in this same stream. For what ever reason, I ran my fly near the bank 3 times before the old boy came up to smash it. He was near 23" long and my biggest trout taken from any Montana stream!!!
The above cutthroat trout came from a similar stream. I think I hooked this slab of a cut 2-3 times over the last 2 years but never landed him till this year. He's a good 16" which is a dandy cutthroat in any one's lair!! I've been told there are a couple more bigger than this fella in this run but I'm happy to have landed and released him to fight another day!!
Most small streams favor attractor type flies vs. true "match the hatch" dry flies. As I said, hoppers are a good food source for small stream trout. On the left is a close imitation. Next is an attractor I found in the "Fly Fisherman" magazine some years back. I think it has caught more trout than any other pattern I have used over the years! Next is the "Humpy" which is a close 2nd to the attractor in success and last is a "Trude" type fly that works well also.
So as long as my old legs will allow, I keep sneaking up my favorite SW Montana trout streams in search of beautiful trout. I'll also remember to sit my old hiney down and take in this beautiful country and give a heartfelt thanks for the many days I have spent enjoying this great sport!! May there be many more! TROUT