Scientists call the land along the edges of a river, stream, or lake a riparian zone. In this guide, riparian zone will be called the Green Zone. Riparian zones make up only a small part of land in the United States. But they are very important. They protect water quality and quantity, supply food and shelter for fish and wildlife, and provide many other services. This guide will help readers explore what Green Zones are and why they are important. It's filled with fun activities that will help readers learn the skills they will need for investigating a local Green Zone. A glossary is included. [For related report, "Holding onto the Green Zone: A Youth Program for the Study and Stewardship of Community Riparian Areas. Leader Guide," see ED527223.]