When I was young and we would walk on the beach of the Oregon Coast, I was told to never, ever turn my back on the sea. It wasn’t a rigid rule, despite the vehemence with which it was given. The rule was more of a guideline; imagine having any kind of fun at the beach trying to keep a constant watch for tsunami or rogue waves. Instead, the idea was to never take geography for granted. Keep an eye out in every direction.

The danger of the ocean was one thing, but one strangely dangerous thing we did was to run along in a primitive kind of parkour over the rocks and driftwood logs piled up by storm surges above the high-tide line. It was an especially stupid game of Lava, but it was fun, so long as you were careful not to jump on something that looked like it could move. “Looked like it could move” is a very bad criteria, but none of us ever fell or twisted an ankle. In hindsight it was still a fairly dangerous thing to do.

There were so many geographical dangers on the beach. The cliffs above were sandy soil and had few “bones” of rock. They sometimes slumped, to the consternation of the retirees who had built their little houses above. There were rocks out in the surf that were tempting to climb on even as the low tide turned. There were particularly deep pools that would be carved out of the sand around particular formations. Rips swirled everywhere.

In various jobs and activities I’ve found myself out in the middle of nowhere on a steep, soggy Oregon slope or in a spectacular road cut. Erosion is supposed to be subtle and small in its individual takings. That’s why mountains get more round as they get smaller. In the absence of the sea or big earthquakes, the rock becomes dirt and the dirt trickles downhill as solute and sand and rubble or is lifted from bald exposure by wind. The humps of the hills themselves stay put. We expect them to stay put. We trust our lives to the idea that the earth doesn’t move, much. And mostly it doesn’t.

I’m thinking today about the people of Oso and all the people who live in the little towns built under and on top of looming geography, like the towns I lived in when I was young.