Fished Upper Rock Creek on 9-24-2011 from 1-6 PM West of Phillipsburg on Hwy 38 N of Georgetown Lake. Just below the bridge caught 3 Cutthroats 8, 11, 15" on a green caddis pupa ext body dropper below a #12 grasshopper attractor. This area holds Bull Trout. I saw a couple in the 30" range but could not get a take, though one chased my 8" cut. Good source of information is the Stonefly Fly shop in Butte. Mike and Chris were very helpful with flies and river accesses. Check their site at www.thestonefly.com.