Continuing eastward, St. Helens' ash fell in the western part of Yellowstone National Park by 10:15 p.m. and was seen on the ground in Denver, Colorado, the next day.
Jauh di timur, abu dari gunung St. Helens jatuh di bagian barat Taman Nasional Yellowstone pada pukul 22:15  malam dan terlihat di tanah di kota Denver, Colorado, keesokan harinya.