The Cascades Volcano Observatory of the U.S. Geological Survey maintains information and links to other sources on all U.S. volcanoes, not just the Cascade volcanoes; its home page is at
One link of special interest describes the USGS's Volcano Disaster Assistance Program, which involves the world's only volcano crisis response team. In cooperation with USAID and other agencies, it has responded to more than a dozen volcano crises since 1986. See
"Volcano World" is a very popular site, maintained with support from NASA to promote public access to and use of space science data, with links to a tremendous variety of information about terrestrial volcanoes and those on other planets, including lists of current/recent volcanic activity. See