Nice photo. It has been acknowledged for quite some time about the browns in Cooper Lake and River. Quite the fish variety there actually. Have heard of cutts, bows, brookies, browns, and kokanee; none of which get stocked regularly anymore.
I'd love to camp up there, but I once read a report recalling the sound of ticks raining down on the tent all night long. Unfortunately, I don't know enough about ticks to suggest a tick-free time of the year. I think the guy was camping at the south end of the lake. Anyone camped there before?
I went there this July for a weekend. We stayed in the walk-in campground (we arrived about 3 pm on Friday and got the last site) and took our 4-yr old grandson and canoe. It is a gorgeous lake and a nice campground, but the fishing is tough. We caught one brown on the weekend, although I must admit I didn't really get much fishing time in. I talked with several other fishermen and the campground host, who fishes it regularly, and all had the same story - very few fish per hour on the water.
I wonder if you fished off the boat launch extremely deep using streamers if you could pick up some larger fish. The fishing was slow but the brown I got to hand was about 12" and a very healthy looking fish.
There were lots of fish rising and feeding. They were feeding on a caddis hatch. I had several hits on a size 16 elk hair caddis. My caddis seemed to match very well the hatch. However after the hatch there wasn't much feeding on the surface. It seemed like there were plenty of fish. Sometimes truly wild trout can be very selective.
Locals poaching has been observed in the past. No cell service up there to call the authorities unfortunately.
It's in a Wild Species Restoration program according to signage present at this time. I haven't fish it in at least a few years. There was a time when significant specimens could be caught if it was approached in the proper manner. Still might be the case?