High Quality Content by WIKIPEDIA articles! The Crater Glacier (also known as Tulutson Glacier) is a geologically young glacier that is located on Mount Saint Helens, in the U.S. state of Washington. The glacier formed after the 1980 Eruption and due to its location, the body of ice grew rapidly, unknown to the public for nearly 20 years. The glacier once contained ice caves in the smooth ice before the post-2004 volcanic activity. The growth of the lava dome and volcanic eruptions since 2004 significantly altered the appearance of the glacier. In the same time period, several agencies decided to put an official name on the glacier which, at first, was Tulutson Glacier. A later decision made Crater Glacier the official glacier name. Despite the volcanic activity, the glacier continued to advance and by mid-2008, the glacier completely encircled the lava domes. In addition, new glaciers (rock or ice) have formed around Crater Glacier as well.