The
David A. Johnston Cascades Volcano Observatory is the
volcano observatory that monitors volcanoes in the northern
Cascade Range. Its territory covers
Oregon,
Washington, and
Idaho. The Cascade range's southernmost reaches extend into Northern
California, and Cascade volcanoes south of the Oregon-California border—such as
Mt. Shasta—previously fell into CVO's jurisdiction. However, as of February 2012, these volcanoes fall under the jurisdiction of the newly formed California Volcano Observatory (CalVO), based in
Menlo Park, CA which monitors and researches volcanic activity throughout California and
Nevada.