I posted this before but can't remember where, but I've found a very tedious, but effective way to catch those browns amongst schools of suckers, and I did it at valley a lot.
If the browns are hanging out with suckers, they are most likely in very slow water. Tie on some midges (do not use anythig less than a #20) and place a little bit or biostrike foam about 3ft from your highest fly (or you can tie on an egg as your top fly to act as an indicator for the dropper). Cast to them like a normal nymph, and watch the indicator for the slightest twitch. If the indicator makes any small movements, set the hook. It'll be a false alarm a lot of the time, and other times you may foul-hook suckers, but you can catch those trout that way.
Last winter I would sit by schools of suckers/browns and use that technique. The key is patience and perserverence. I would probably spend 3 hours with one school, maybe throwing 100 casts at them, and get 2-3 browns. Might not be the most efficient method of fishing, but it worked for me.....
