I stood atop Sentinel Dome, perched high above Yosemite Valley. It was one of many rounded globes of granite in the High Sierras, and likely the one most easily accessible by car. The sun was poised to set, hovering low in the west and bathing the blue-grey stone and evergreen pines in a warm, golden glow. My legs were singing from the hustle up the trail, and my heart was soaring. I wasn’t alone on the dome, not by a long shot. Small clusters of European tourists - taking ad