The grains in these rocks may look like crystals that fit together like jigsaw puzzle pieces. [Illustration: MARBLE] [Illustration: GRANITE] [Illustration: Department of the Interior · March 3, 1849] As the Nation’s principal conservation agency, the Department of the Interior has responsibility for most of our nationally owned public lands and natural and cultural resources. This includes fostering sound use of our land and water resources; protecting our fish, wildlife, and biological diversity; preserving the environmental and cultural values of our national parks and historical places; and providing for the enjoyment of life through outdoor recreation. The Department assesses our energy and mineral resources and works to ensure that their development is in the best interests of all our people by encouraging stewardship and citizen participation in their care. The Department also has a major responsibility for American Indian reservation communities and for people who live in island territories under U.S. administration. This publication is one of a series of general interest publications prepared by the U.S. Geological Survey to provide information about the earth sciences, natural resources, and the environment. To obtain a catalog of additional titles in the series “General Interest Publications of the U.S. Geological Survey,” write: U.S. Geological Survey Information Services P.O. Box 25286 Denver, CO 80225 Transcriber’s Notes —Retained publication information from the printed edition: this eBook is public-domain in the country of publication. —In the text versions only, text in italics is delimited by _underscores_. End of Project Gutenberg's Acid Rain and Our Nation's Capital, by Elaine McGee