Geologic Forces at Mount Rainier

Follow this Quest to explore the immense forces that build up and tear down great mountains. Witness the results of volcanic eruptions, massive avalanches, moving glaciers, and catastrophic floods, and see the miracle of recovery and re-growth.  

Mount Rainier is a huge mountain shaped by huge forces. It is a live volcano built up over time by repeated eruptions. Its 14,411-foot summit gives birth to 25 glaciers that plow their way down the mountain, relentlessly tearing it down. In spite of their power, these glaciers have been surrendering to another force– global climate change. It is possible that this change could bring more devastating floods like the one in 2006, caused by 18 inches of rain in 36 hours.

Melting glaciers, eruptions, or rocks weakened by volcanic heat and gases can trigger massive flows of mud and debris, known as lahars, which have periodically roared down Rainier’s slopes. Snow avalanches can race down the mountain at speeds of up to 300 mph.

But each natural catastrophe is also an opportunity for life to begin anew. Plants and animals quickly enter newly cleared areas to establish new ecological communities. As you view the geologic impacts highlighted in this Quest, marvel at the miracle of rebirth and renewal around you.


Discovery #1  Sunrise        

View the exhibits in the visitor center to learn about Rainier’s battle between fire and ice and use telescopes to get close-ups of glaciers. Rangers can direct you to the short Emmons Vista Trail where two spectacular viewpoints reveal the massive Emmons Glacier. Beneath the right shoulder of the summit, look for a large concave marking the origin of the Osceola mudflow. About 5600 years ago it removed as much as 2000 feet of the mountain’s height and swept it down the White River all the way to Puget Sound.

Quest activity:  Use the “passport” stamp at the information desk of the visitor center to stamp the date and location on this sheet:

 

Discovery #2 Ohanapecosh

At the end of Loop C of the campground, view the devastation caused by a 2006 mudflow originating high above the river. You can see how it flattened trees and washed away several campsites.  Notice the “pioneer plants” that have re-grown in this area. From the back door of the visitor center, you can take the 0.4-mile loop trail to see hot springs bubbling up from the ground, heated by volcanic fires.

 Quest activity: Use the “passport” stamp at the information desk of the visitor center to stamp the date and location on this sheet:

 

Discovery #3 Box Canyon        

Box Canyon testifies to the erosive power of water. From the parking lot, walk onto the road bridge that spans the canyon. The force of the Cowlitz River carved this deep gorge into solid rock.  Between the restrooms and the canyon edge, look for parallel scratches (“glacial striations”) created by the grinding action of glacier ice as it moved down the mountain.  You can see more of the glacier’s work if you take the short trail across the road from the parking lot.

Quest-ion:  What is the distance from the road surface to the water in the canyon?  (Hint: see the sign on the bridge railing.)

 

Discover #4   Stevens Creek Avalanche    

Where the Stevens Canyon Road makes a sharp turn and begins to climb to Reflection Lakes, see the path of the huge avalanche that swept down Stevens Creek in 2009, knocking down trees as it flowed across the road. Such avalanches can travel as much as 300 mph!

Quest-ion:  What can you see has happened since 2009?

 

Discovery #5     Paradise

Learn about the power of volcanoes and glaciers in the upstairs visitor center exhibit hall.  “Restless Giant”, the free movie in the lobby theater, highlights forces of nature on the mountain and shows an actual mudflow (“lahar”). The rangers can direct you to the Nisqually Vista Loop trail (1.5-mile round-trip; 60 min.; moderate) to view the Nisqually Glacier. Once there, look for the rocky debris below and huge walls of rocks alongside the glacier—massive amounts of material dragged down the mountain by the glacier, then abandoned as it melted back. You can take a free ranger-led geology walk on this trail in summer, or a snow-shoe tour in winter (snowshoes provided).

Quest activity:  Can you find pebbles of volcanic pumice rock on the trails in this area? They are the result of past volcanic eruptions and lava flows.

 

Discovery #6    Narada Falls

You can view the falls from the edge of the parking lot, or take the short, steep trail to viewpoints below.  The wrinkled lava rock walls are the result of past volcanic eruptions of Mt. Rainier.  Quest-ion:  What gouged out this deep canyon?  (Hint:  Check the sign along the viewpoint trail.)

Quest-ion:  What gouged out this deep canyon?  (Hint:  Check the sign along the viewpoint trail.)

A few minutes’ drive downhill of the falls takes you to Glacier Bridge, where a wall of mud and water tore out a previous concrete bridge in 1934.

 

Discovery #7    Longmire  

At Longmire you can view volcanic hot springs bubbling up from the ground—evidence of this still-simmering volcano. Stop at the museum for directions to the springs on the Trail of the Shadows.  Quest activity: Ask the museum ranger for photos of the flood of 2006, when a storm dumped 18 inches of rain in 36 hours.

Use the “passport” stamp at the information desk of the visitor center to stamp the date and location on this sheet:

 

Discovery #8   Kautz Creek

As you drive west from Longmire, stop at the Kautz Creek picnic area. Signs across the street explain how in1947 a wall of mud up to 60 feet tall swept down the creek.  It diverted the creek and left the “ghost” trees you now see and.

Quest-ion: At what speeds do Mt. Rainier’s mudflows travel?

 

Discovery #9   Westside Road

You can drive the first three miles of the Westside Road to a parking area (usually open June through October). The rest of the road is now closed to vehicle traffic after being repeatedly devastated by powerful floods and debris flows. Continue on foot from the parking area, on what’s left of the road, to see disconnected pavement, shredded old-growth trees, giant log jams, and large boulders imbedded high in trees by a torrent of water, mud, and rocks in 2006.

 Quest-ion: Can you tell how high the flood waters rose?

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