Not far from my house, there is a river of rocks. I could see two patches of it pretty clearly from this vantage point on Hawk Mountain in Kempton, Pa.
The story of this river goes back to the Pleistocene Epoch, the Ice Age that ended about 11,000 years ago when glaciers left the rocks here. There is a trail along the "river" that I have yet to hike.
As I research Glacier Bay, Alaska and Yosemite Valley in California, I find this local connection to a similar geological process utterly fascinating.