I was there a couple of weeks ago and had the same water conditions. I caught several nice fish but I fished hard all day to catch what I did on a variety of flies and techniques. I've seen a lot of posts, similar to yours, and talked to several people that reported similar experiences. I think the number of fish, are still there. However, I think the current water conditions are spreading the fish out all over the lake/river. There are pods of fish, all over the river, you have to cover more water to get to them.