Evidence You Were There

​Mountain streams cut V-shaped valleys. Mountain glaciers cut U-shaped valleys. Both erosional agents leave evidence they were there, once doing work. The streams might have dried up long ago, and the glaciers might have melted, but their valleys remain. The character of a geological agent is evident in its product. Some agents, however, merely move through an area without much effect. Wind gaps are cuts in mountains where once water or ice eroded but now serve only as passageways for the air that, unlike the winds in deserts and beach environments, does little work. The wind passes through the gap, the notch in a rocky ridge.
 
You can, if you wish, merely pass through an opening cut by a previous human agent. Or, you can make your own notch in the hard world around you, providing an easy passage for those that follow.