The Camping Trip That Changed America by Barb Rosenstock illustrated by Mardicai Gerstein

Two very different men, Theodore Roosevelt and John Muir, find commonality in their love for nature.  Roosevelt responds to Muir's request to come see the beauty of the wilderness in California and after that camping trip, proposes and changes laws to protect America's wilderness.
Beautiful vertical illustration of the sequoias. 
Points to discuss: Muir's belief in evolution