1. Department of Geosciences University of Arizona 1040 E. 4th Street Tucson Arizona 85721 USA
2. University of Florida Water Institute 570 Weil Hall Gainesville Florida 32611 USA
3. Sonoran Institute, México Calz de las Americas 233, Cuauhtémoc Sur Mexicali 21200 Mexico
4. The Nature Conservancy, Colorado River Program 2424 Spruce Street Boulder Colorado 80302 USA