Muddy Fork landslide of 1859?

[Chase]

Just looking for info about the Muddy Fork landslide that happened in the mid-1800's (probably from the eruptive activity of 1859, possibly the activity of 1865). I guess this was something of a whopper of a landslide, but Google and my usual reference books aren't giving any info. Anyone able to add anything? Super thanks!

[Peder]

Chase - I came through there yesterday and the area sure seems rather unstable! There was also a mudflow (?) some years back that moved the Ramona Falls TH a mile or two downstream. I look forward to reading any responses you may get.

[payslee]

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[Chase]

Time for a follow-up on this thread.

I emailed Payslee's friend, Scott Burns, and he had this to say:

You are probably talking about the "Old Maid Flats" Eruption that occurred in 1872. It was the last eruption of Mt. Hood. It had a large lahar (debris flow which you called a mudslide) that originated in the Muddy Fork and came down the Sandy River to Troutdale.

I believe he had a typo in there and meant 1772.

My interest in there is the forest buried under the Muddy Fork (near the present day PCT crossing, I believe). If it is from the Old Maid Flats eruption, Splinty has covered this in his blog regarding the White River side of the volcano.

http://wyeastblog.org/2011/09/18/white- ... ed-forest/

So the rumblings in 1859 and 1865 were probably not responsible for the Muddy Fork forest being buried. When I started this thread, I was under the impression that it might have been a later landslide that buried the forest-- something post Lewis & Clark. Thanks for putting up with my self-indulgent need to know this stuff. I already knew quite a bit about the Sandy River becoming "sandy" from the Old Maid Flats eruption, but thought the Muddy Fork stuff might be independent of that.

[forestkeeper]

Hey Chase. You sparked a geology interest. How far, would you estimate, is that forest under the earth? And, would it be buried? Wouldn't a landslide push the existing forest in outward directions? I would think that the only way a pre existing forest would be covered is if it was submerged with a flood, covered with an eruptive nature, or covered with an Ice Age nature, then resubmerged by any of the latter processes. Wouldn't a landslide, in contrast with an avalance, destroy whatever is in it's path? It would be fun and interesting to do a small dig to discover what plant and animal species are down there. Please post your findings.
Will

[kepPNW]

A lahar is really an entirely different scale than we normally envision when we think of a landslide. And it's less viscous, too, so it wouldn't naturally mow something over as much as it might just flow right around and over it. Sort of a "mud flood," I suppose.

That all said, I have no idea about this one in particular. I've heard it said that Spirit Lake Lodge is 300 feet underground, right now, though, for a gauge of what's possible.

[justpeachy]

There's a little nature trail at the Lost Creek Campground and it has interpretive signs describing the geologic activity in the area. It's actually pretty cool and informative.

[oldandslow]

This week in the course of printing a picture of Mt. Hood from the Muddy Fork, I came across a photo that appears to show four buried trees near where the PCT crosses the Muddy Fork.

[Chase]

Yes, that's what I was a'talkin' about!

[payslee]

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