Could always head to the Mammoth Lakes area. Hit Convict, Hot Creek... list goes on there.
I was up there on the 4th weekend and the water was so high and fast by Devil's Postpile that we could barely wade. We caught a few there as well as Convict Creek, but nymphing Hot Creek gave us the best results. Strangely we only saw 3-4 other people both days we were there.
I'm dying to get back up there. Where Allen suggested has been on my list for some time now.