John Muir (2015). “STEEP TRAILS: California - Utah - Nevada - Washington - Oregon - The Grand Canyon: Adventure Memoirs, Travel Sketches, Nature Essays and Wilderness Studies from the author of The Yosemite, Our National Parks, A Thousand-mile Walk to the Gulf & Picturesque California”, p.45, e-artnow
John Muir (2015). “STEEP TRAILS: California - Utah - Nevada - Washington - Oregon - The Grand Canyon: Adventure Memoirs, Travel Sketches, Nature Essays and Wilderness Studies from the author of The Yosemite, Our National Parks, A Thousand-mile Walk to the Gulf & Picturesque California”, p.45, e-artnow