This occurred forty-odd years ago while my late wife and I were camped on the deserted site of a gold mine at Chancellor just south of the Pasaytan Wilderness border in Washington's North Cascade Mountains.

Pat and I had explored the site's ruins and were returning to our campsite along a dirt road bounded on our left by Slate Creek and on our right by a steep cutbank covered by brush and a number of dead fir trees. We had just passed a small side road when Pat abruptly stopped and cried out "What is fluttering around my head?" I saw nothing there, and assured her of that, but she insisted that she could feel the beating of wings. I stepped close to reassure her, and at that moment  for no discernable reason ( it was a windless day) one of  the dead trees toppled from the bank and across the road in the approximate place where we would have been had Pat not stopped to question that sensation of fluttering wings.