Had a fantastic full-on fast track tour of the National Parks USA lasting 16 days, over 3000 miles, I counted we went through 7 States and several time zones, our days kept getting longer. We started off in Las Vegas in over 100 degrees of heat which never really abated for the whole tour. Walked through Zion Canyon, walked around the rim of Bryce Canyon, through Arches National Park, but the altitude and heat were a challenge. I would say don't do this tour if you aren't fit. Its a very fast turn around in the evening to get back out for dinner, very early rising to be on the coach for 8/8.30 a.m. every day, and lots of one nighters in hotels living out of a suitcase. Our tour guide Wendy was full of information and nothing was too much trouble, in fact sometimes she had to be a sheep dog herding some of us back on the coach. Holiday of a lifetime but not for the faint-hearted, I just about managed it!