America's Granite Dome Mountains

Tom Wessels is a professor of Ecology at Antioch New England Graduate School in Keene. His book, "The Granite Landscape," studies granite dome mountains in America from New England to Yosemite. He explains what granite domes are, and how they're formed. He also writes about the unusual ecosystems that develop atop these unique mountains. "The Granite Landscape" is published by Countryman Press. This interview originally aired in June.