Yellowstone's Hydrothermal Wonders: By the Numbers

Yellowstone National Park hosts the world's largest concentration of hydrothermal features—over 10,000 in total.

• Geysers: ~500 (300+ active) – half the world's total. Old Faithful, Steamboat, Grand, Castle.
• Hot Springs: Thousands – including Grand Prismatic Spring (largest in US, 3rd world).
• Mudpots: Acidic, clay-rich, bubbling (e.g., Fountain Paint Pot, Artists' Paintpots).
• Fumaroles (Steam Vents): Hissing steam, often superheated (e.g., Roaring Mountain).
• Travertine Terraces: Mammoth Hot Springs – limestone deposition.

Major basins: Upper (Old Faithful), Midway (Grand Prismatic), Lower, Norris, West Thumb, Mammoth. All driven by the Yellowstone hotspot's shallow magma chamber heating groundwater.