On the way to town from my house there is a place along the highway where an entire mountainside slipped into the river during the recent flooding. Before, it was covered with trees, as you can see on the edges of the scar.
This is how it started along the riverbank. That ledge got washed away, and then the river just nibbled on the footing of the slope until it was gone, and the rain-saturated slope slid away. To a smaller degree, this is what happened along the side of my upper driveway.
This is one of the flood sights that disturbs me the most - to think of that entire mountainside slipping away, and all the rocks, dirt, and trees going down the river to hit up against houses, bridges, and the riverbank.