Library of Congress
The Conservation Movement at a Crossroads: The Hetch Hetchy Controversy
Should wilderness areas be preserved or managed? Class members examine primary source documents, including lecture notes, articles, essays and congressional records to better understand the Hetch Hetchy controversy that created a split...
US Geological Survey
U.s. Geological Survey: Where Is Earth's Water Located?
Find out how much of the water on Earth is actually usable by humans, and where the rest of it is located. Learn where our water comes from and why it never runs out. Click Home to access the site in Spanish.