Frasier78, so sorry you don't like Sacramento and had a bad experience on your first weekend. We moved to the area 8 years ago and love it here. Yes, I've heard that there are a lot of trashy people who do raft rentals on the lower American, and so our family hasn't gone there, yet. But all of the greater Sacramento area is not "foul." Renting a kayak at Lake Natomas is lovely, and the upper American River is where we spend most of our summers. And I've heard that the lower American river tubing/floating is at its worst on holiday weekends. I haven't been, but now with your comment, we'll be trying it out to give some firsthand feedback!
Hope you will be happy back home in Colorado. Sometimes moving to a different place IS a culture shock - it was for me, moving from urban Southern CA. But I just wanted to say, although you have a different opinion, my opinion is that all of Sacramento is not a foul place, in fact, just the opposite; most of it is VERY nice; there are a couple of places that attract foul people, just like in any city. But, to each their own.
Ruth: are you sure you are rafting on the North Fork in July? North Fork is a wild river and not dam controlled. It usually dries up to a trickle by end of May/beginning of June (my dh works for a rafting company). Maybe you are going on Middle Fork? Whoo-hoo! Tunnel Chute, how fun is that???!!
Another option for tubing is in Tahoe City (the northwest part of Lake Tahoe). It's about 1.5 hours away, gorgeous scenery. They rent you the tube, and you go on your own, and they have a bus bring you back.
Have fun!