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Near Greenwater in Pierce County, Washington — The American West (Northwest)
 

Mud on the Move

Osceola Mudflow

— Mather Memorial Parkway —

 
 
Mud on the Move Marker image. Click for full size.
Photographed by J. J. Prats, May 17, 2015
1. Mud on the Move Marker
Click on image to zoom in to explore the diagrams.
Inscription. Mud on the Move. Along with lava and ash, the volcanically active Mount Rainier has contributed thick flows of mud from its sides and summit. One of the largest mudflows occurred about 5,800 years ago sending thick rivers of mud down the White River drainage.

These flows carried rock and huge boulders, some 35 feet tall and several hundred feet around, from the mountain’s slopes to the surrounding lowlands.

Osceola Mudflow. The largest of the mountain’s historic flows, the Osceola mudflow covered an area of about 100 square miles. It buried the present town site of Enumclaw (24 miles west of here) under as much as 70 feet of debris.

Seismic activity triggered the mudflow, resulting in the collapse of nearly 2,000 feet of Mt. Rainier’s summit.
 
Erected by Mt. Baker-Snoqualmie National Forest.
 
Topics. This historical marker is listed in this topic list: Natural Features.
 
Location. 47° 3.166′ N, 121° 34.325′ W. Marker is near Greenwater, Washington, in Pierce County. It is on Chinook Pass Highway (State Highway 410) 7½ miles south of Greenwater, on the right
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when traveling west. It is at the scenic pulloff. Touch for map. Marker is in this post office area: Enumclaw WA 98022, United States of America. Touch for directions.

Regionally, this marker is in the Puget Sound Region and in Greater Seattle. It is also on the American Pacific Coast, in the Pacific Northwest, and in the Lewis & Clark Corridor. Globally, it is in North America, in the Cascade Range, in the Inside Passage, on the Ring of Fire, in the Pacific Rim, in the Western Hemisphere, in the Western World, and in the Anglosphere.

Other nearby markers. At least one other marker is within walking distance of this marker: Why is the River White? (here, next to this marker).
 
Mud on the Move and Why is the River White? Markers image. Click for full size.
Photographed by J. J. Prats, May 17, 2015
2. Mud on the Move and Why is the River White? Markers
The Mountain – Mt. Rainier image. Click for full size.
Photographed by J. J. Prats, May 17, 2015
3. The Mountain – Mt. Rainier
 
 
Credits. This page was last revised on June 16, 2016. It was originally submitted on June 15, 2015, by J. J. Prats of Powell, Ohio. This page has been viewed 549 times since then and 42 times this year. Photos:   1, 2, 3. submitted on June 15, 2015, by J. J. Prats of Powell, Ohio.
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Sep. 10, 2026