My planned "summer of constant camping" amounted in the end to one trip, taken with good friends to the second of two lakes called "Lake Ann" that I know of in Washington. This one is east, in the Snoqualmie region (the other is up north of Seattle near Mount Baker / Mount Shuksan, and I was there a few years ago). The terrain is not identical for sure, but both have a lot of interest for day hikes around them.