Quote:
is there just... one mountain there?


Yes. Just one big stratovolcano - all 14, 400 feet of it (and that's missing the 2000 feet it blew off its top). Takes your breath away, in person, when you're close to it.

It was, of course, built during multiple eruptive phases.

I'm including information on the mountain, below for your edification.

Here is the definitive USGS page on Mount Rainier.

vulcan.wr.usgs.gov/Volcanoes/Rainier/

Poster-style graphic showing the extent of Mount Rainier's historical mudflows here:

vulcan.wr.usgs.gov/Imgs/J...ectron.jpg

Brief description of its eruptive history, taken from the above site:

Mount Rainier is an active volcano that first erupted about half a million years ago. Because of Rainier's great height (14,410 feet above sea level) and northerly location, glaciers have cut deeply into its lavas, making it appear deceptively older than it actually is. Mount Rainier is known to have erupted as recently as in the 1840s, and large eruptions took place as recently as about 1,000 and 2,300 years ago. Mount Rainier and other similar volcanoes in the Cascade Range, such as Mount Adams and Mount Baker, erupt much less frequently than the more familiar Hawaiian volcanoes, but their eruptions are vastly more destructive. Hot lava and rock debris from Rainier's eruptions have melted snow and glacier ice and triggered debris flows (mudflows) - with a consistency of churning wet concrete - that have swept down all of the river valleys that head on the volcano. Debris flows have also formed by collapse of unstable parts of the volcano without accompanying eruptions. Some debris flows have traveled as far as the present margin of Puget Sound, and much of the lowland to the east of Tacoma and the south of Seattle is formed of pre-historic debris from Mount Rainier. -- Sisson, 1995

Best,
Dean
Better to have loved and lost than to be married to a PSYCHO.