1. Civil and Environmental Engineering Syracuse University 151 Link Hall, Syracuse NY 13244 U.S.A.
2. U.S. Geological Survey, Southwest Biological Science Center 2290 S. West Resource Boulevard, Moab UT 84532 U.S.A.
3. Department of Plant and Wildlife Sciences Brigham Young University 5048 LSB, Provo UT 84602 U.S.A.