The landmark in central Oregon isn't a former military base; it's an ancient volcanic eruption in the middle of what was once the middle of a freshwater sea. Read more: https://www.kgw.com/article/travel/destinations/grants-getaways/fort-rock-state-park/283-0224dafc-3d6f-4f27-957d-4b768d1986d3 Subscribe: https://www.youtube.com/c/KGWNews8 Watch the latest KGW newscast: https://www.kgw.com/watch Get the KGW app: https://kgw.com/appredirect