The Pinnacles: Wiggins Formation
Having lived for 10 years in Jackson Hole and having taught geology in that part of the state…. I enjoy the scenery on a whole different level
One the Highway between Dubois and Moran Junction there is the “Breccia Cliff” that I’ve always known as “The Pinnacles”. They are a magnificent exposure of Volcanic Lahar flows (hot glowing cloud of volcanic debris) layered one on top of the next. It is a geology classroom all around this country but don’t try to climb that hill. It’s always having avalanches and rock falls in that country.
I’ve been up to it’s base but it took a day on horseback to do it. Do not try that on foot, it’s way further back than you think. Unforgiving country. Grizzleys hang out there now.
The rock there is basically a blender mix of tuft, scoria, a volcanic conglomerate as it were. Chunky pieces, angular all suspended in a fine grain matrix of volcanic rock. This formation is seldom found below 10,000 feet in elevation on the eastern margin of Jackson Hole. The formation is up to 3000 feet thick in this country. That’s a lot of Lahars….. You can drive right to this picture spot on Highway 287 and pull over on this meadow along the side of the road. Click
There are some wonderful lakes in this area. This is snowmobile recreational heaven in that country. Big Groomed trails along the divides cover this area. There are a few campgrounds and a lodge or two in the area. This is pristine northern Wind River Range backcountry visible right off the road.
Location: Hwy 287, 30 miles north of
Dubois on Togwatee Pass.
Title: The Pinnacles: Wiggins Formation