"The Drumheller Channels are the most spectacular example in the Columbia Plateau of basalt "butte-and-basin" channeled scablands. This is an erosional landscape characterized by hundreds of isolated, steep-sided hills surrounded by a braided network of (usually) dry stream channels. The landscape is the result of dramatic modification of the Columbia Plateau volcanic terrain by late Pleistocene catastrophic glacial outburst floods—the Missoula Floods. These floods occurred at a scale remaining unparalleled on earth, either in the geologic record or in historical account. There are 150 distinct channels and over 180 rock basins in this region. Many of the low areas, including Upper Goose Lake, are filled by water seeping in through cracks in the basalt bedrock, which are connected with Potholes Reservoir to the north."
"The floods formed Drumheller Channels in much the same way as they did the smaller Othello Channels: by forcing the water to go around the nose of the Frenchman Hills but within the boundaries of the Palouse Slope. The height of the floodwaters was about 150 feet different between the upper and lower parts of Drumheller Channels. This significant difference in water level generated tremendous erosive power that scoured the complex network of channels, buttes and basins here. However, unlike most other areas in the Channeled Scabland, no central channel or dominant cataract developed; instead, floodwaters passing through behaved more like a broad cascade-up to 12 miles wide!"
The mixture of lakes and surrounding irrigated croplands, combined with mild winters and protection provided by the refuge, attracts large numbers of migrating and wintering mallard ducks, Canada geese and other waterfowl, including tundra swans.
Some information provided courtesy of Bruce Bjornstad's first book on the Ice Age Floods-"On the Trail of the Ice Age Floods, a geological field guide to the Mid-Columbia Basin".
Other sources of information on the floods and the geology of the area include:
Hanford Reach National Monument Geology Pages
National Park Service Ice Age Floods Report
National Park Service Drumheller Channels National Natural Landmark Site
To claim this EarthCache please email me the answers to the following questions:
1. What type of rock are the Drumheller channels eroded into?
2. How many distinct channels and rock basins are in this region?
3. Using both the information in the description and on the info plaques at the viewing point, how did the Drumheller Channels form?
4. How wide were the floodwaters as they passed through the channel?
5.Estimate the elevation difference between the viewing point you are standing at and the lowest elevations you can see below.
***PHOTOS OF YOURSELF AND OR YOUR GPRS AT THE LOCATION ARE ENCOURAGED BUT NOT REQUIRED!!***
Also, don't forget to grab GCNC78-" Micro Madness #3- Mother's Day" while you're here if you haven't already!
 This cache was placed by a WSGA member. If you are a geocacher in the state of Washington, please consider joining Washington State Geocaching Association. See the WSGA website for details. |