Coldwater Lake and the Hummocks Trail
Sep. 10th, 2022 09:58 am![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
canyonwalkerPacific Northwest September Travelog #10
Mount St. Helens National Monument - Sun, 4 Sep 2022, 5:15pm
"What else should we do in the park after hiking Johnston Ridge to Devil's Point?" I asked a ranger at the visitors center.
"I always like seeing Coldwater Lake," she said. "It's so pretty. And my favorite trail in the park is the Hummocks Trail. You get to see the geologic features up close and personal."
So that's what we did after our main hike.
Forty years ago Coldwater Lake was Coldwater Creek. Debris flow from the Mount St. Helens eruption several miles away formed a natural dam blocking the stream's flow. Within a year the valley filled with water to a depth of 200'. The near end is shallow, though. A delta of volcanic ash is present here. The kids playing in the water were all exclaiming how weird the ground feels under their feet. Yeah, kids, that's not sand!
After the 1/4 mile or so nature walk we did at Coldwater Lake we laced up our boots for a longer hike on the Hummocks Trail. Well, I laced up my boots. Hawk went in hiking sandals. It would be a bit over 2.5 miles.
A hummock is a small hill that's actually a broken off piece of the mountain. Hummocks were deposited miles away in the debris flow that followed the volcanic eruption. In the photo above you can see Mount St. Helens in the distance. In the near- and mid ground are many of these hummocks. Geologists know they're broken-off bits of the mountain because the rocks types match.
The most interesting views of hummocks, IMO, are where the North Fork Toutle River nearby has cut away the volcanic ash around them. This valley was covered up to 200' deep under ash and mud. The river is gradually carving a channel through it.
Mount St. Helens National Monument - Sun, 4 Sep 2022, 5:15pm
"What else should we do in the park after hiking Johnston Ridge to Devil's Point?" I asked a ranger at the visitors center.
"I always like seeing Coldwater Lake," she said. "It's so pretty. And my favorite trail in the park is the Hummocks Trail. You get to see the geologic features up close and personal."
So that's what we did after our main hike.
Forty years ago Coldwater Lake was Coldwater Creek. Debris flow from the Mount St. Helens eruption several miles away formed a natural dam blocking the stream's flow. Within a year the valley filled with water to a depth of 200'. The near end is shallow, though. A delta of volcanic ash is present here. The kids playing in the water were all exclaiming how weird the ground feels under their feet. Yeah, kids, that's not sand!
After the 1/4 mile or so nature walk we did at Coldwater Lake we laced up our boots for a longer hike on the Hummocks Trail. Well, I laced up my boots. Hawk went in hiking sandals. It would be a bit over 2.5 miles.
A hummock is a small hill that's actually a broken off piece of the mountain. Hummocks were deposited miles away in the debris flow that followed the volcanic eruption. In the photo above you can see Mount St. Helens in the distance. In the near- and mid ground are many of these hummocks. Geologists know they're broken-off bits of the mountain because the rocks types match.
The most interesting views of hummocks, IMO, are where the North Fork Toutle River nearby has cut away the volcanic ash around them. This valley was covered up to 200' deep under ash and mud. The river is gradually carving a channel through it.
