Comprehensive encyclopedia providing personal and professional information on some 444 American and Canadian naturalists, explorers, conservationalists, ecologists, environmentalists, scientists, writers, and artists from the late 15th century through the present. The editors are professional historians and professors who have placed each subject within the framework of the evolution of environmental science, from early exploration to current governmental regulation. Concise, clear, and unbiased, the entries average two pages and very clearly outline biographical information, professional and career accomplishments, and major contributions.