Before revision: WOVO.org: World Organization of Volcano Observatories Originally, the volcano observatory was known as the Long Valley Observatory which monitored volcanic activity east of the Sierra Nevada in Mono County, California which included Long Valley Caldera, Mammoth Mountain, and the Mono–Inyo Craters.
After revision: Originally, the volcano observatory was known as the Long Valley Observatory which monitored volcanic activity east of the Sierra Nevada in Mono County, California which included Long Valley Caldera, Mammoth Mountain, and the Mono–Inyo Craters.