Roaring Mountain near Norris, Yellowstone National Park, 1936

Yellowstone National Park, established 1872, was America's first national park. Roaring Mountain, near Norris Geyser Basin, is named for the sound of steam fumaroles that became very active and noisy in 1902, killing a mountainside of trees. It no longer roars but it still has many steam vents and hot sulphurous rivulets that trickle down its face.