Wherein Moominmama explores what it means to live on a volcano and worries about snow...

Yellowstone National Park has its own Grand Canyon, but one that was formed differently than the famous Arizona canyon. The Yellowstone canyon walls are surreal: sulphur yellows, pinks, whites and reds created by geothermal fluids. Harder to see in the two dimensions of a photo are the many pinnacles that jut up on the sides, called hoodoos.

Created by volcanic action, the canyon provides a path for the Yellowstone River below, adding erosion to the mix. This is reportedly what created the famous Upper and Lower Falls. 

The rhyolitic lava and tuff on the canyon walls erode at different rates, with the Upper Falls featuring harder rock. The water carved its path, creating the large Lower Falls from the softer rock.

While the park contains many grassy fields, winding creeks and forested vistas, its geothermal origins are hard to escape. The volcanic caldera on which Moominmama lives for the next few weeks is constantly changing. Yellowstone is considered to be a "hotspot," which sounds less like magma and more like menopause. But it refers to an area where heat from the earth's core can break through the planet's crust.

When researchers in 1984 compared the surveyors' measurements from 1920 used to design the park roads, they found parts of the caldera had bulged up more than 3 feet. Newer technologies now confirm there is continuing movement -- a breathing of the volcano, of sorts, throughout Yellowstone.

And it is odd to drive around and see pillars of steam rising from the ground. Visiting some geothermal features nearby, I got to see churning, bubbling hot water, steam erupting from vents and mud pots that burble and fart. Much of it is sulfurous, which is to say it smells like rotten eggs. 

One of my favorites was the Dragon's Mouth -- a cave where the hot water roars and groans and hisses like a dragon, creating steam that billows out like breath. The Crow people, one of many indigenous peoples to hunt and visit the area, saw the steam as snorts from an angry bull bison. That works too!

Signage along the paths and boardwalks around the "Mud Volcano" area repeatedly warn people not to step off the path. This is a living, burning, baking landscape. An area of dead trees is labeled the Cooking Hillside. And it's obvious the park service has had to reroute the path for tourists when some of the geothermal features shift.

Here's broken pavement, to the left of the new boardwalk, that ends abruptly approaching a recent vent (or fumarole). It makes me wonder about the people who built these walkways and how carefully they had to step when they worked!

After looking at all these wonders all the warnings and all the evidence that the land is continually shifting, you feel like you really are walking on top of a volcano. It's a bit unnerving.

Old Faithful, the geyser that shoots up at predictable intervals, now seems like an anomaly. But my visit to Old Faithful and the other famous geothermal features in the southwest side of the park will have to wait for another day next week.

I head back to making beds at the Lake Lodge, detouring around the bison that go wherever they dang well please, and listening at night to the noise of rutting elks. From a distance, they almost sound like whales calling out. But one that entered the RV park a few nights ago woke me up from a sound sleep with his bugle-like cry. Definitely not a happy elk. 

I am also worried about the forecast for snow tonight, which seems surprising when the landscape is frequently at the boiling point!

 
I am taking steps to keep my water pipes from freezing and bought a little electric heating pad to keep my battery happy. At most, we may get a few inches and no deep freeze. (Sunday afternoon update: it has started snowing!)

Yellowstone is full of surprises, and a sense that the ground is not always so firm beneath my feet.