Once upon a time, I flew in a small plane over the northern reaches of Minnesota in winter.

I had never seen a frozen river, nor expected to see so many lakes— also frozen—appearing from above as small white lozenges pressed into the land. Flying low there’s a myriad of tracks and lines on the landscape—marks made by man and beast and by nature itself; all manner of scratchings and ruttings and paths picked out, revealed and highlighted by snow.