I've been trying to follow the "Sisters bulge" story for a while. Do you know of any sources that are following this that I can periodically check? Thanks.
Try the home page for the Cascades Volcano Observatory, a USGS website dedicated to the volcanoes in the Cascade Mountains range.
http://vulcan.wr.usgs.gov/ This home page has links to a large amount of information on volcanoes and the entire USGS internet prescence. I find it quite valuable.