Ansel Adams may not have considered this when he shot and printed Moon and Half Dome, Yosemite or any of the other thousands of images he made at Yosemite National Park. The damage may not be in what men bring to the park, but in what happens when it falls apart. We camped at Yosemite this weekend - at one point about eight of the guys trouped out onto a boardwalk across a meadow to drink beers, make ridiculously long shutter exposurs of each other drinking, and to watch the full moon rise. The screw was sticking about half an inch up out of the boardwalk, where it had been extracted by the ceaseless pounding of millions of tourists' feet each year. I pulled on my beer and considered it, a little woozily. It was loose. If I left it there, someone would surely come along and either blow a tire or stub a toe. If I pulled it out, I'd be an agent of entropy, a force for decay. I hesitated a bit, then pulled it out, having just recently come through a patch of wickedly bad kharma involving my own bike (drove it - while it was on my car's roof rack - into a low-hanging steel-and-stucco carport, about which the less said, the better). The other item - a milky white glass insulator - glinted up at me from amid the granite stones in the bed of the stream that fed down from the foot of Lower Yosemite Falls to the Merced River. It was almost hidden in the icy, fast-running creek that swirled around my ankles. If I had left it there, perhaps it would have sunk back into the streambed, forever part of the landscape. Perhaps it came from a felled powerline or phone pole somehwere much farther north along the river. No matter. It's on my desk now.