Yellowstone National Park: Location, Geology, and Wildlife Across Three States

Yellowstone National Park—the world's first national park (1872)—spans 3,472 sq mi (8,991 km²) primarily in Wyoming (96%), with slivers in Montana (3%) and Idaho (1%). Its boundaries encompass one of Earth's most extraordinary geothermal and ecological landscapes.

Geographic Framework

The park sits atop the Yellowstone Plateau (average 2,400 m / 7,800 ft elevation), bounded by mountain ranges: Gallatin (NW), Absaroka (E), Teton (S), Madison (W). The Continental Divide crosses the park diagonally—rivers west flow to Pacific, east to Atlantic (via Missouri-Mississippi).

Geothermal Wonderland

Yellowstone hosts half the world's geothermal features:

• 500+ geysers (including Old Faithful)
• 10,000+ hydrothermal features total
• Hot springs, mud pots, fumaroles, travertine terraces

Fueled by the Yellowstone Caldera—a 70x45 km supervolcano with three major eruptions (2.1M, 1.3M, 0.64M years ago) and ongoing magma chamber activity.

Iconic Wildlife

Mammals (67 species): Grizzly bears, gray wolves (reintroduced 1995), bison (largest free-ranging herd), elk, moose, pronghorn, bighorn sheep, mountain lions, lynx, wolverines.

Birds (285+ species): Trumpeter swans, bald eagles, peregrine falcons, sandhill cranes, great gray owls.

Fish: Yellowstone cutthroat trout (native), lake trout (invasive threat).

Visitor Access

Five entrances: North (Gardiner, MT), Northeast (Cooke City, MT), East (Cody, WY), South (Jackson, WY), West (West Yellowstone, MT). Grand Loop Road (230 km figure-8) connects major basins.

Yellowstone's tri-state location, volcanic heart, and intact ecosystem make it a globally unique natural laboratory and wilderness sanctuary.