The San Francisco volcanic field around Flagstaff [right] has a moderate threat for eruption, but every state in the Southwest has a volcano hazard.
There's a good analysis on MSNBC.com of last month's Southwest volcanic hazards conference in Flagstaff. Of the 1,400 volcanoes in the Southwest, at least 600 are in the area around Flagstaff. Arizona has more in the Uinkaret volcanic field in the Springerville area.
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