Ranger Eileen explains to park visitors how and why Sequoia trees grow. She covers nitrogen, oxygen, hydrogen and carbon, the purpose of leaves and the layers within a tree trunk. The book is aimed at elementary through middle schoolers with clear bright full page illustrations opposite each page of text. I challenge you to pick up a copy of Out of Thin Air and further challenge you to put it down! In my career of bringing nature to children and adults through wildflower and field trips, I found this a great way of introducing trees to all. I thoroughly enjoyed it. - Stephen K. Stocking, author of Wildflowers of Sequoia and King s Canyon National Parks Giant Sequoias are unique and special inhabitants of the Sierra Nevada mountains from Sequoia National Park, Yosemite National Park, Calaveras Big Trees State Park and beyond. Out of Thin Air is an excellent introduction to the important role trees have to earth and to the global ecosystem of the planet. - Mary Anne Carlton, M.A., Park Ranger, Sequoia National Park Unlike many other children s books about Giant Sequoias that focus on the great size and age of these trees, Out of Thin Air clearly illustrates the complex chemical and biological processes that are necessary to grow a Big Tree. Teachers will find this to be an excellent tool that will engage their students interest in new science concepts using the big trees as a real world example. I highly recommend this book to any teacher who is planning to bring their students on a field trip to visit the Giant Sequoias. - Wendy Harrison, Interpreter, Calaveras Big Trees State Park