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| Gros Ventre Slide of 1925 looking south across Gros Ventre River |
I visited a curious part in Wyoming yesterday, so unlike the rugged Wind River and Teton Ranges, yet near them—east of the Tetons and north of the Winds. The area was known for centuries as having minor earth tremors and small landslides, and was considered by some to be spooky.
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| Slide of 1925, 95 years after, huge rocks still showing |
But in 1925 it drew national attention for a massive landslide along the Gros Ventre River, pronounced "grow-vont." Within fifteen minutes, a mass of rocks, soil and trees slid from the south canyon wall, rumbled across the river and didn’t stop before going three hundred feet up the other side. The slide was a mile long, half a mile wide, and left a dam across the river 225 feet high. Geologists think that a shale layer became slippery and allowed everything above it to slide.
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| Tensleep Sandstone in the rubble |
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| Tensleep Sandstone in the rubble |
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| End of the rubble 300 feet up the far bank |
A slide of this magnitude did not occur in previous millennia, probably because the Gros Ventre River had not cut through the Amsden Shale, removing the one holding force against a slide.
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| Slide Lake, looking upstream |
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| Slide Lake, looking downstream, Slide scarp in background |
The lake created upstream by the slide, Slide Lake, is still here and is still held in place by material from the 1925 slide. But it was not always so. Two years after the slide, part of the dam was over-topped sending a tremendous flood rushing three miles down the canyon, wiping out the small town of Kelly, killing six people. But in the past ninety-three years the dam has held.
On another day, I
stood at the foot of another kind of slide.
I imagined a gigantic wall of ice that was the leading edge of a
glacier. Perhaps it moved to where I
stood sometime in a past ice age, then hesitated and retreated, only to move
downward again as climate changed. In
one of its retreats it delivered this boulder, as part of its accumulated baggage, brought from far upstream, as if delivering it to me for my perusal and pleasure. The glacier might have slid forward and
melted backward several times before finally depositing this particular
boulder, but eventually its retreat became a final motion, and the glacier was
finished. The rock slide remains.
Michael Angerman is
making a map of nightly locations, as he has done for many of my trips. Please see Michael's Map
















































