1. US Geological Survey Upper Midwest Water Science Center, One Gifford Pinchot Drive,, Madison, Wisconsin 53726, United States
2. US Geological Survey Columbia Environmental Research Center, 4200 New Haven Rd, Columbia, Missouri 65201, United States
3. U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200SW Jefferson Way, Corvallis, Oregon 97331, United States
4. National Park Service, Air Resources Division,
P.O. Box 25287, Denver, Colorado 80225, United States
5. Appalachian Mountain Club, 361 Route 16, Gorham, New Hampshire 03581, United States