A recent study published in the AGU Journal investigated the crustal-scale structure beneath a section of the Cascades arc, which spans four major stratovolcanoes.
Washington has the fourth-most amount of volcanoes in the United States.
Here's something I found out today. Alaska has 141 "potentially" active volcanoes, by far the most in the United States. Oregon is the third-most volcanic state with 17...
It is National Park week which means free entrance to all national parks. Mt. Rainier national park which is a quick 3 hr. Drive from Tri-Cities has some of the most picturesque views you'll ever see and well worthy of a visit or many visits for that matter.