Is It Camouflage?

Hikers in Colorado kept seeing this huge black spot in a cliff up at the ridge of these really, really high mountains. He finally noticed that one day the shadowas not there, but the sun's in the same position. So he started taking photos on a time release, and he saw this enormous like, the doors just opened up and a flying object came in. The doors closed, but they were in the side of the cliff, so they just looked like a stone wall. Oi, i used to have a friend that would come over to my house and deliver firewood for me. And he said on a number of occasions when he was either hunting or cutting firewood,