This book describes the causes and aftermath of Mount St. Helens' 1980 eruption. Short paragraphs of easy-to-read text and plenty of colorful photos help readers stay engaged and supported. The book also includes a table of contents, fast facts, sidebars, comprehension questions, a glossary, an index, and a list of resources for further reading. Apex books have low reading levels (grades 2-3) but are designed for older students, with interest levels of grades 3-7.