Mima Mounds aerial video

A ground-skimming helicopter flight over the Mima mounds west of Centralia is captured in this video posted by KING 5 news. The title of the video is ‘What are the Mima Mounds” but the video offers no insights; there is no discussion or explanation of any kind. The only audio is the helicopter blades. The spaces between the mounds is covered with snow, but the tops of the mounds are either melted out or wind blasted clear of snow. NOTE: you’ll have to wait for the thankfully-short furniture ad to finish before seeing the main attraction. If you enlarge to ‘full screen’ mode, the mound video will end but continue seamlessly to more irritating commercials. I couldn’t easily figure out how to get out of that.

Thanks to Wendy Bowlin for sending this along.

I’ll have an entire chapter about the Mima mounds and the many hypotheses concerning their formation in my book, Geology Underfoot in Western Washington. While you are breathlessly waiting for me to finish writing and get published, read Dan McShane’s discussion of the mounds on his website, Washington Landscapes.

In a related note, the Washington State Department of Natural Resources is seeking public comment on a proposal to expand the boundaries of the Mima Mound Natural Reserve. Read about it here.

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6 Responses

  1. This is a first for me! I have never, ever seen anything on TV that doesn’t have constant babble. What is the rule of broadcasting….never have even five seconds of dead time because people will change the channel or station?
    It is indeed odd that there isn’t a narrator mentioning various hypotheses of formation of the mounds including gopher mounds, Indian burial sites, and submarine fish nests. It is odd with no talking, but refreshing! And I kinda like the muffled drone of the chopper, because choppers are cool.

  2. Mima-like mounds are also a common feature on flood-scoured basalt of eastern Washington. Gene Kiver and I discuss their formation in our new book coming out by Keokee in the next few months. Title: “On the Trail of the Ice Age Floods: The Northern Reaches”. We believe Mima mounds are multigenetic – some are only a few hundred years old.

    Bruce Bjornstad

    • Bruce,
      Thanks for your comment about mima mounds in E WA. I’ve seen plenty of them over there, as well as in central Oregon, and photos from western Texas even. In my book chapter on them, I go over many of the hypotheses, mostly monogenetic, that have come up over the decades. I’ll be interested to see your discussion in your new book, which I’ll also review on this website and help people find out about it.
      Dave

  3. Thanks for passing this on. Very cool footage. I am of the view the term Mima mounds should be restricted to the mounds of the southwest Washington priarie. The mounds in eastern Washington may be of similar size, but the mechanism of formation is clearly different and perhaps a bit better understood. I would note however that the mounds in eastern Washington are not restricted to flood scoured areas.

    • Dan,
      The term ‘Mima-like’ mounds has been used in some papers to differentiate those from the southern Puget lowland from others elsewhere. Please explain to me and to other readers what you mean by “the mechanism of formation is clearly different and perhaps a bit better understood”. To the best of my knowledge, no widely accepted explanation for the formation of ANY of these mounds, regardless of location, has been put forward.
      Dave

  4. I Given the shocking amount of literature on mounds all over the place and my not being in the loop of what is widely accepted this is a tough request. But I’ll give it a bit of a go. First, the term Mima. When I hear or see the term Mima or Mima-like my reaction is the mounds are being compared to the mounds of Mima Prairie. Which, at least for me, is confusing when the underlying geology, climate and most likely processes are completely inapplicable to the mounds at Mima Prairie. I kind of like what Kaatz (1959) did by calling the mounds he was discussing Manastash Ridge mounds.

    I’m with Washburn in that I do not think there is a grand all encompassing mound theory that explains all mounds. Using the term Mima-like confuses the issue of mounds in a given area in my mind.

    The Manastash Ridge mounds brings me to another reason I commented. I see references to mounds located on Missoula Flood scabland terrain; indeed there are mounds in the scablands; however, they are widely present on areas well above the flood areas such as on Manastash Ridge and on the high upper slopes above the Snake River and multiple other locations.

    The widely accepted part is a tough nut to address. But at least in my own mind many of the eastern Washington mound areas are erosional. The exact process may not be entirely nailed down, hence, my use of “perhaps a bit better understood”. I am of the view there are likely multiple ways to bring about mound formation in an erosional setting. Furthermore, I lived in eastern Washington and used to go running, hiking and hunting in some of the mound terrain and have observed surface water flow in mound areas – a rare event and wind – a not so rare event.

    I may not know what the threshold of widely accepted, but I am pretty comfortable with the erosion idea with an open mind as to various causes as to why some of the soil remains in place. I even find the gopher story making sense for some of the mounds – with the idea that they did build the mounds but aid in the erosional process between the mounds.

    From a literature perspective, I found the following influential in my own thinking:

    Waters, A.C. and Flagler, C.W., 1929 Mounds of the Columbia Plateau, American Journal of Science, 18: 209-223.

    Kaatz, M.R., 1959, Patterned ground in Central Washington: a preliminary report, Northwest Science 33: 145-156.

    Kaatz, M.R., 2001, 1998 Debris Flows near Yakima River, Kittitas County, Washington – Some Geomorphic Implications, Washington Geology, Vol 29, No 3/4: 3-10

    (I should note that the two Kaatz papers are not consistent and should be read in conjunction. Kind of cool how he recognized a new process over a previous view that was more aligned with peri glacial processes. He does not specifically address mounds in the second paper, but the location and the other features shows the importance of intense rain fall events on the eastern Washington landscape and happens to be located in an area of mounds as the source area of water flow)

    Cox, G.W. and Allen, D.W., 1987, Sorted Stone Nets and Circles of the Columbia Plateau: A hypothesis, Northwest Science, Vol 61, No. 3: 179-185.

    Hallet, B, and Sletten, R.S., 1994, Mima Mounds: Constraints in the timing of formation, GSA Abstracts and programs, 1994 Annual Meeting, Seattle, Vol 26 (7).

    (I simply like the admonition that some thought should be given to ongoing processes. That is something has to be going on to maintain the mounds shape. Hard to have a mound of dirt simply sit there for 12,000 years)

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