Kitsap Waterfall Survey: "Dickerson Falls"

This will probably be my last Kitsap Waterfall post for some time due to being at Central Washington University for the next several months, but I wanted to get it out before the summer.

I have made the decision to combine two waterfalls, "Cleft Falls" and "Cable Falls" on Dickerson Creek. I was able to visit these two falls on my last major waterfall survey after I found "Melange Falls" and "Cedar Gorge Falls" (which will have a write up about them in the summer or fall.)

My reasoning for combining these two falls is that they are extremely close together, mere feet. So in hindsight, I think they are really two drops of one large fall. My reason for not deciding to do this when I first discovered them is, quite simply, I was inexperienced and hadn't made up my "requirements" for the survey. So now, I'm going back and correcting that.

So, since both of these falls are being combined, the names "Cleft" and "Cable" are going to be dropped and I'm going to rename this waterfall "Dickerson Falls" after it's source creek, and since that's what the Ueland Tree Farm calls it. It is also sometimes referred to as "Chico Falls" by locals.

The upper horsetailing tier of "Siletzia Falls" at moderate flow. Photo by Micah K. 

"Dickerson Falls" begins immediately after Dickerson Creek pours over a small abandoned concrete dam which backs up the creek to form Beaver Dam Lake. The first tier cascades five to ten feet before horsetailing over a large basalt shelf around 20 feet into a large plunge pool, which is frequently used as a swimming hole during the summer. After exiting the plunge pool, the second tier begins. The second tier cascades 20 to 25 feet over a big buttress of blocky basalt, it's rather ugly: crisscrossed with huge downed trees and several old logging cables. Below the falls the creek heads into a narrow gorge with some smaller cascades and rapids, before continuing down the canyon.

Geomorphology of the northern Thorp Region

The small hamlet of Thorp, Washington, lies about 14 minutes to the west of Ellensburg as the cwu geology van drives. It is located in the Yakima River Valley, the namesake of which meanders it's way north of Thorp slowly making it's way southeast. 

Today I ventured out on a field trip with my Geomorphology class to observe some of the Geomorphological features of the area. What is Geomorphology? Just break it up! Geo=Earth, Morph=Change, and Ology=To Study. So putting it all together, it's the study of landforms created through geologic processes. 

The first feature we observed was the most interesting to me personally. Almost 2.8 miles due north and a little west of Exit 101 on Interstate-90, is a large hillside comprising of ancient Yakima River Sediments. At this point, 1.5 to 5 thousand years ago, the hillside failed. Possibly driven by weak clays or saturated soils, a massive rotational-slump type landslide broke loose. The resulting earth flow at the foot of the slide shoved the Yakima River south by several hundred feet. 

Looking across the large landslide north of Thorp. Photo by Micah K. 

From an overlook at the western edge of the landslide, my Geomorphology class looked across this landslide. The displaced material had taken on a hummocky appearance, with the blocks tilted slightly towards the failure headwall. The size of this thing was boggling, even while small in comparison with the landslide that, for example, decapitated Mount Saint Helens in 1980 with catastrophic results. Even the several houses that were built on top of the landslide deposits seemed small in comparison. It was truly amazing.

Northwest of Thorp, Interstate 90, climbs up another large slope and across the wide, rolling expanse of basalt boulders and sagebrush known as the Thorp Prairie. It's strangely empty up on this expanse, only being occupied by several old and dilapidated windmills, and crisscrossed by irrigation canals. The reason for this emptiness being most in part for it's geology. Thorp Prarie sits on a massive terminal moraine formed many thousands of years ago when a large glacier flowed down the Yakima River Valley. The heart of this moraine is filled with rocky glacial garbage, scraped out from the mountains and dumped here as the glacier retreated, too rocky to farm on, and not very suitable for irrigation, this, it has remained relatively untouched. 

As the Yakima River carves it's way through this moraine to the north, over thousands of years it has created several large flood terraces visible on the flank of the moraine and elsewhere in the valley walls. These large flat expanses are sometimes built directly on top of Columbia River Basalt, which is exposed in the deepest parts of the canyon by the river. And as luck would have it, I'm going to see a important portion of the Columbia River Basalt tomorrow. So...to be continued......

Erosional Remnant of the Columbia River Basalt. Photo by Micah K. 

Coming full circle, The surprising relation between Kitsap Waterfalls and Yellowstone Geysers.

It's no secret that my two favorite things on this earth are Yellowstone's hydrothermal features and the Kitsap Peninsula's hidden waterfalls. One takes my attention during the summer, the other takes my attention during the wetter months of the year. Two separate geological features, nearly 900 miles apart, with seemingly no relation between them. Or so I thought...

I have just finished wrapping up my first week of classes here at Central Washington University, and am loving it. My classes are fascinating, my professors are great, and it's looking like the quarter is going to be one adventure after the other.

During on of my classes, "The Geology of the Pacific Northwest" this week we were discussing two of Washington's major geologic events. The Columbia River Basalts, that covered 40% of the state in up to 3 mile thick layers of lava rock. And the huge glacial floods that tore their way out of Montana and roared across the flat plateau of eastern Washington, all the way to the Pacific.

The origins of the Columbia River Basalts were 18 million years ago when the Yellowstone Hot Spot made it's first continental appearance, tearing massive calderas into what is now northwestern Nevada, southeastern Oregon, and Southwestern Idaho. For years I had thought that these first explosive eruptions were the birth of the Yellowstone Hot Spot. When I asked my professor this, he informed me that recently it had actually been suggested that the Yellowstone Hot Spot is much older, and has been erupting for longer than is commonly thought.

As it turns out, there are several studies which show the Yellowstone Hot Spot originating off the ancient west coast of the Pacific Northwest. For those of you who have been to my waterfall lecture, something should begin to feel eerily familiar about this....

As I explained in my lecture, 55-57 million years ago, some unknown force split the ancient Farallon Plate into several pieces and erupted a huge amount of basalt lava onto the seafloor. These basalts, today known as the "Crescent Formation," were slammed into the side of the North American Plate and stuck there, uplifting to become modern day Vancouver Island, part of the Oregon coast ranges, the eastern Olympic's, and the core of the Kitsap Peninsula. It is now believed that the "unknown force" was none other than the Yellowstone Hot Spot. That's right, the bedrock comprising Green and Gold Mountains, and the rest of the Blue Hills, the same bedrock that our beloved waterfalls crash over, probably originated from the geological feature which fuels Old Faithful, Beehive, and the other 1500 geysers in Yellowstone National Park.

Micah the Wildcat, a new chapter for Geologic Adventures

Hello readers,

For the past several months, Geologic Adventures has been dominated by my work with the Kitsap Waterfall Survey. For the time being, that project must come to a temporary halt. This week I started a new quarter at Central Washington University, signalling the beginning of a new chapter for my life. I've left behind the crashing cascades and green ferns of the Puget Sound region and am now writing this post in the hot, semi-arid climate at the eastern foot of the cascade range. 30 minutes away, the mighty Columbia River meanders past the massive basaltic flows of the Columbia Flood Basalt province which covers 40% of Washington State, erupted some 17 million years ago.

For those of you who have been following this blog for updates on the Kitsap Waterfall Survey. Do not fear! The survey is not over. I have plans to continue my waterfall investigations whenever I go back to Kitsap County to visit between school quarters. So the survey will be continuing, just at a much slower pace than before.

Back to the present, I am currently taking three geology courses at Central Washington: Geomorphology, Stratigraphy, and Geology of the Pacific Northwest. All three of these classes have field trips associated with them. So this blog will have plenty of content to be filled with as the next ten weeks progress.

I'm excited for this next step in life, and am looking forward to sharing my geologic adventures with all of you!

Micah

The Wildcat of Central Washington University