6 months traveling the western half of the U.S.A.

My dad was lucky enough to get a six month sabbatical from his work. So my parents decided that we would travel the western half of the U.S.A. instead of traveling abroad, since we have done that more than traveling in our own country. We have a 15 passenger van, (we took out the last row in order to fit all our stuff in the back). My dad and grandpa drove the van down from our house in Alaska to Arizona. 10 days later my mom, my siblings and I flew down to meet my dad (grandpa flew home before we got there).