We did 2 days of rafting -- the first day was from Ashcroft to Spences Bridge, the 2nd day from Spences Bridge down to Lytton, where the Thomson River joins the Fraser. On a BC map, you'll find these on Hwy #1, between Kamloops and Hope.
We went through various rapids, experiencing everything up to class 4's on our 2 days with Drew, our guide.
Make sure you check the two rafting pictures (first picture, second picture). The names of the rapids on the Thompson River are interesting: The Frog, Green Holes, Washboard, Devil's Kitchen, Cutting Board, Garborator, Witches Cauldron and Jaws of Death.
(Needless to say, Kat stayed at the campsite this time, though she really wanted to participate. Send me e-mail if you want to know why Kat stayed at the campsite!)