Yellowstone National Park, established by act of Congress on March 1, 1872, is a part of the high country of the middle Rocky Mountains containing geysers, hot springs, and other thermal features which are the result of volcanic activities prevailing in the area for ages. Yellowstone is the largest and oldest of our national parks, with an area of approximately 2,213,000 acres of federally owned land, lying in the extreme northwest corner of Wyoming. It includes within its boundaries small portions of Idaho and Montana. The average elevation of the park is between 7,000 and 8,000 feet. Both the surrounding mountains and the interior plain are composed largely of material once ejected as ash and lava from depths far below the earth's surface.

Precautions, warnings, roads and trails, free public campgrounds, season and accommodations, medical and miscellaneous services.

Information on features of the Park.