Casting a wide net, this volume provides personal and professional information on some 445 American and Canadian naturalists and environmentalists, who lived from the late 15th century to the late 20th century. It includes explorers who published works on the natural history of North America, conservationists, ecologists, environmentalists, wildlife management specialists, park planners, national park administrators, zoologists, botanists, natural historians, geographers, geologists, academics, museum scientists and administrators, military personnel, travellers, government officials, political figures and writers and artists concerned with the environment. Some of the subjects are well known. The accomplishments of others are little known. Each entry contains a succinct but careful evaluation of the subject's career and contributions. Entries also include up-to-date bibliographies and information concerning manuscript sources.

"Modern American Environmentalists" profiles the lives and contributions of nearly 140 major figures during the twentieth-century environmental movement. Included are iconic environmentalists such as Rachel Carson, E. O. Wilson, Gifford Pinchot, and Al Gore, and important but less expected names, including John Steinbeck and Allen Ginsberg.

The entries recount how each individual became active in environmental conservation, detail his or her significant contributions, trace the influence of each on future efforts, and discuss the person's legacy. The individuals selected for the book displayed either an unparalleled commitment to the conservation, preservation, restoration, and enhancement of the natural environment or made a major contribution to the growth of environmentalism during its first century.

With a foreword by environmental historian Everett I. Mendolsohn, a time line of key environmental events, a bibliography of groundbreaking works, and an index organized by specialization, this biographical encyclopedia is a handy and complete guide to the major people involved in the modern American environmental movement.