1. U.S. Geological Survey, Oklahoma-Texas Science Center Austin, Texas 78751, United States
2. U.S. Geological Survey, Colorado Water Science Center Lakewood, Colorado 80225, United States
3. U.S. Geological Survey, California Water Science Center Sacramento, California 95819, United States
4. U.S. Geological Survey, Headquarters Reston, Virginia 20192, United States
5. U.S. Geological Survey, Washington Water Science Center Tacoma, Washington 98402, United States