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The CREST locations were given spatial extents through use of GIS software, since the planning document gave only general text descriptions of locations (the authors had to manually search 1: 1,000,000 aeronautical charts). Based on the slightly different criteria (stated above) and more sensitive mapping with GIS software, we identified five additional potential target areas. The Bureau of Reclamation 1980 report I identified the entire Mogollon Rim in Arizona as a potential target, whereas we exclude all of it (except for the San Francisco Mountains) because it is largely below 9000 feet elevation. The snowfall at such low elevations, particularly if they are at southerly latitudes as in Arizona, would frequently occur at relatively warm subfreezing temperatures during which silver iodide would be ineffective. Seeding by liquid propane gas expansion, which can create ice crystals at warmer temperatures (thresholds -20C vs -60C for silver iodide), might be a viable alternative for such locales. An essential point is that, despite the CREST criteria application, there is still substantial subjectivity in selecting any seeding target area. All new potential areas are listed in Table 3. Both existing and potential areas are shown by the map in Fig. 1 (online version with indexed areas in combined table). Table 3. Potential Target Areas Colorado Utah Wyoming Arizona 15. Park Range 20. Uinta Mtns. 24. Wyoming Range 26. Kaibab N.F:W- North 16. Elkhead Mts. 21. La Sal Mts. 25. Wind River Mtns. West" 27. Chuska Mts. (AZINM) 17. White R. 22. Mt. Ellen" 28. White Mts. Plateau 18. Uncompahgre 23. Abajo Pk. " 29. San Francisco Plateau Peaks' 19. Central Rockies@ Areas not Identified In CREST document @ Area was operationally seeded in previous years by Denver Water utility 2.2 Nature of Calculations For the current application, we integrated SNODAS 1 km SWE data over seeding target areas at the traditional end of the mountain snow accumulation season, April 1 (also the traditional beginning of the snowmelt runoff season). To estimate water volumes produced by seeding in potential areas, these integrations are divided by ten, since there is statistical, physical and modeling evidence for about 10 percent augmentation of natural precipitation (snowfall) by orographic cloud seeding9. Physical cause-and-effect relationships have yet to be fully demonstrated, however. Since seeding has been conducted in existing areas, it is assumed that SNODAS SWE already reflects the 10% increase, or 110% of natural snowpack. Therefore the integrated SWE is divided by 11 in these areas. These calculations were made for both 2004 and 2005 April 3