In response to [log in to unmask], I, too, recall finding strange
bits of silvery foil material in the woods near our home north
of Utica, NY.  I associate this with the late '50's or early '60's,
civil defense drills and air raid selters.  My sister and I scooped
up a handful of the feathery material and took it home. My mother
(who was certain that we would glow in the dark) contacted the local Air
Force Base in Rome, Griffiss AFB, and discovered that its affiliated lab,
Rome Air Development Center (RADC), was conducting radar evasion
experiments.  Apparently, the fine particles of silver material
were scattered around the planes to disguise them from radar -
or something like that.  The planes flew out of Rome but could
easily have traveled quite a distance.  Several years ago,  I shared
this memory with someone from Rome Lab (formerly RADC) who confirmed
that they were a center of great activity in radar research during
the 50's & 60's.  I can imagine a number of interesting tales were
spun from that mysterious silver 'fallout'.