The term Mount __ (Washington) is completed by the crossword solution of Rainier, which is a stratovolcano located in the Cascade Range of Washington State. It is the most prominent peak in the continental United States and is the highest mountain in the Cascade Range. The volcano is named after Peter Rainier, an English soldier and explorer. It is one of the most dangerous volcanoes in the world due to its large amount of glacial ice and its potential for producing lahars, which are mudflows that can cause destruction in the surrounding area.