1. U.S. Geological Survey, Oklahoma City, Oklahoma 73116, United States
2. U.S. Geological Survey, Iowa City, Iowa 52240, United States
3. U.S. Geological Survey, Reston, Virginia 20192, United States
4. U.S. Geological Survey, Columbia, South Carolina 29210, United States
5. Oklahoma State University, Stillwater, Oklahoma 74078, United States
6. U.S. Environmental Protection Agency, Ada, Oklahoma 74820, United States
7. U.S. Geological Survey, Lakewood, Colorado 80225, United States
8. U.S. Geological Survey, Sacramento, California 95819, United States
9. U.S. Geological Survey, Madison, Wisconsin 53711, United States
10. U.S. Geological Survey, Kearneysville, West Virginia, 25430, United States
11. U.S. Geological Survey, Lawrence, Kansas 66049, United States
12. U.S. Geological Survey, Boulder, Colorado 80303, United States