We went West last year from Houston and did Colorado, AZ, and Utah. It was a National Parks tour so we did not do any rafting. Depends on what kinds of rafting you are looking for. I've done Cache Lapoudre which was great in June and been rafting in Durango. The closer to the main meltoff the more whitewater you get especially with a deep snow pack. You can also do a gentler raft trip down the Colorado out of Page AZ south of Glen Canyon Damn. Our trip took us to Great Sand Dunes in Co first then up to 70W (stop in and see family) then Grand Junction, follow CO river to Moab which was awesome but Arches NP was hot in August for the hiking. Zion was warm but enjoyable and Bryce was very nice and pretty cool at night. Hit a bunch of places in Utah and AZ and ended up coming home with a stop in Grand Canyon than through Flag to Amarillo and then 287. Good luck. We have so much fun just planning the trips.