We have quite a few groups that spend a week on the Situk, it is a great easy drift with lot's of fish, but can get real low in the summer so you might be walking some.
There is about 3 groups that come in April and early May and camp on the river and fish Steelhead, it can be cold that time of year and as much as I like Steelhead, I don't think I would spend a week camped on the banks of the Situk at that time of year, I like my warm dinner at the lodge and soft bed after a long day of fishing!