The Copper is a glacier river and always nasty fast looking, mainly dip netters for fishing and fish wheels, quite the dangerous river for certain, big boats and power is needed most of the time, but the shear number of fish that utilize it is amazing. If you want a very good time put in a float on it mid Oct, if it isn't starting to freeze, you'll see bears at almost every sand bar thriving on old salmon carcasses washed up on the back side of the bars. On the other hand the the Russian is a mountain fed river and a feeder river to the Kenai, the only reason it would have dirty looking is probably a couple days after a major rain, it is normally crystal clear and running well. Fishing the Russian is awesome, I like it after the tourist go home (I guess I'm one of those now) and the Reds (Sockeyes) are really RED, just for catch and release or try for specific big fat Rainbows lurking below the salmon thriving on the eggs. Not uncommon to catch 40-50 a day and toss in a few big rainbows, well satisfaction guaranteed. Lots of bears, especially up by the falls.... And of course the two resident cubs in the picture (momma is dead along with one of the cubs) that now are full grown that run up and down into everyones, fishing stuff and bags... Sooner or later someone will take them out as they get too comfortable with being around people...