I have never fished Yakima R. springers, but when the Wenatchee R. was open for springers they were by far the best biting springers I have ever fished for. In some of the more popular holes you would sometimes see 5 to 10 fish on at a time. It was mostly a bank drift fisherie with eggs, shrimp and herring the most used. From what I have experienced the upper Columbia R. trib. springers are much better biters than lower Columbia R. trib. springers. I sure miss the Wenatchee R. springers.