When the Land Turned Green: The Maine Discovery of the First Land Plants

Deep in the wilderness of northern Maine in the mid-1950s, a Harvard PhD student is wading down a mountain stream into a remote valley. He is taking his first steps to map the geology of 300 square miles of Baxter State Park. He soon discovers a series of unusually shaped rock outcrops—part of an unknown geologic formation, hundreds of millions of years old, still mystifying today because of its relative lack of change despite nearby volcanic activity and massive land movement. Wading on, h...