Lewis & Clark: Great Journey West (2002)

At about 40 minutes, this IMAX film is the shortest entry here and a smart choice for the youngest viewers. Jeff Bridges narrates as actors retrace the expedition to the Pacific and back, with river and mountain scenery made for the giant screen. Sacagawea and the Native Americans the party met are part of the story, which gives older kids an opening to ask whose land the journey crossed. The scariest moment is a bear chasing the men after a missed shot, and it is rated G in the US.