I was moose hunting on the upper Selawik River in NW Alaska and found a Teletubbies mylar balloon hung up in the tundra. I spotted it flashing in the sunlight with my spotting scope and had to hike over and see what it was. Seemed odd to be out there. The Selawik River flows along the arctic circle.
On the same trip, I spotted a 50 gallon drum 1/2 submerged in a lake.... The drum was labeled "Avaiation Fuel US Fish and Wildlife Service". The lake was too small to land a plane on, and too far from the river to pack.