I've caught lots of different fish in there over the years but it depends on the year and the season, to a large extent. I'd discourage fishing in July and August because the water temps are so high that C&R fishing could kill the trout. Used to be nonstop largemouth bass in the summer months but they all died off 5 or 6 years ago and I haven't caught one since.
I've caught rainbow, cutthroat, and bull trout, crayfish (on hook and line
), black crappie, sunfish, largemouth bass, pikeminnow, mountain whitefish, and a peamouth chub-related fish that I forget the name of at the moment. Also juvenile steelhead, coho, and chum in the spring months. Spotted a lynx or bobcat in there a few years back, and there are tons of birds: Ana's hummingbirds, herons, kingfishers. There's lots going on in there, despite all the road water and pollutants being washed in, the illegal dumping of paint cans and other chemicals, the runoff from the XTL warehouse, and the homeless camps where people use the river as a toilet. Please be gentle on the poor river
Finding the right spots is more important that what you're throwing.
Yes there are crayfish. I personally wouldn't eat anything out of there because of the pollutants mentioned above. Some people do, though.
Remember, no retention of wild trout. No fishing or retention for any type of salmon. Good luck!