Located within the confines of Ohanapecosh Campground in Mount Rainier National Park, Ohanapecosh means "looking down on something beautiful or clear water" in the local Native American language. In contrast, after the debris flows that occurred here early February, 2006 this area was anything but! "
Mount Rainier stands as the most recognizable feature in Washington's diverse landscape. At 14,411 feet, this mighty mountain towers nearly 8,000 feet over its neighboring peaks, this makes it visible from nearly every corner of the state. The mountain has been a standard feature of Washington's history before it was "discovered" by Captain George Vancouver. Many local native tribes included the mountain in their stories and legends.
Although the mountain's presence has been a constant throughout human history in the region, that presence has also been an ever changing one. Mighty Mount Rainer is, after all, an active volcano and, more importantly, (on a human scale, at least), it's an imposing geological feature whose sheer size and prominence not only attracts strong weather systems but also helps create wild weather. Geologic change isn't so much a matter of slow, steady change. Rather, it's like a war: long boring periods of calm are broken by random moments of extreme activity, sheer chaos, and ruin.
The latest of these chaotic moments occurred during November 5 and 6th, 2006. After one of the driest summers in Washington State's history a slow moving "Pineapple Express" storm brought heavy rains and mild temperatures. A Pineapple Express is a tropical jet stream from Hawaii that moves across the eastern Pacific, gathering moisture before unloading in the mountainous Northwest. A record amount of rain-18 inches in 39 hours fell on the park. The rain and gale-force winds wreaked havoc on the environs of Mount Rainier National Park, changing the courses of rivers, toppling acres of trees, moving mountains of mud and destroying a great deal of the man-made structures within the park. (See also the Sunshine Point earthcache, GC1GDPC, for more information on the damage done to that area.) One of the results of the flooding was the formation of debris flows throughout the park.
A debris flow is a liquid landslide with more soil, rock and organic material than water. It can travel faster than a person can run and can carry boulders as large as a van. Large debris flows can destroy bridges, roads and houses. Debris flows are caused by a combination of water saturation and flow; loose, heavy earth materials; and steep slopes. Concave slopes such as gullies or ravines are particularly susceptible to debris flows because they tend to concentrate surface water runoff and accumulate loose soil and debris. Debris flows can be initiated when small landslides, excess erosion, or failures of man-made or natural dams occur in a mountain stream or gully. By the time a debris flow reaches a creek fan, the volume of debris can amount to tens of thousands cubic meters. Debris flows are most often triggered during intensive periods of rainfall that follow prolonged rainfall that results in wet soils.
Debris flows initiate on steep slopes (initiation zone) and travel rapidly down confined channels (transportation zone), where they can entrain large and heavy debris such as boulders and logs. Once the flow reaches a flatter or less confined area (deposition zone), it will spread out,
lose speed and deposit the large debris.
To qualify as a "find", email (do not post online) the answers to the following questions. Failure to do that in a timely manner will result in a log deletion.
Park at the 30 minute parking or follow the signs to all day parking if you desire to explore the park further. Walk through the campground to the posted coordinates that will take you to an interpretive sign.
1) Using the interpretive sign, what is the only thing that is constant on the mountain and what two aspects of it vary?
2) From where you are standing make at least three observations on how the debris flow from February 2006 altered and impacted this area.
Please UPLOAD a photo showing yourself at the interpretive area, not giving away any answers of course!
Due to seasonal limitations this earthcache is only available during the warmer months, late May to early October when the road and campground are open to the public.
We hope you have learned a thing or two about debris flows and thanks for visiting Mount Rainier National Park!
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Warning: Earthcaches come with a unique set of rules and activities that must be met
before successfully logging. Failure to comply will result in a log deletion.
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