@Tricia and I are fortunate enough to get to spend time and ski with this crew every year at the U.S. Ski & Snowboard Hall Fame Ceremonies. Not only does the movie cover how freestyle and hot dogging started, it talks about the progression up through the years to where we are today.
Searching around Amazon Prime I found this. If you are not a Prime member, it can be purchased on iTunes for $12.99. A great addition to any ski porn collection.