Illustrations produced as a part of this study were made using CorelDRAW® and/or Adobe Illiustrator®. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Personnel to contact about a specific subject are listed on the staff page.
U.S. Department of the Interior
U.S. Geological Survey
221 North Broadway, Urbana, IL 61801, USA
Last modified: 16:15 CST Thurs 11 May 2000