Steamboat Geyser, Natural geyser in Norris Basin, Yellowstone National Park, US

Steamboat Geyser sits in the Norris Geyser Basin of Yellowstone National Park at 2,303 m elevation and is the world's tallest active geyser. Its two vents, about 6 m apart, differ: the north vent throws the tallest water columns, the south vent's are shorter. Major eruptions last 3 to 40 minutes and can exceed 91 m, with the highest measured jet at 130 m, followed by steam for up to 48 hours.

Steamboat was dormant from 1911 to 1961. Activity resumed with 29 eruptions reported in 1964, a calendar-year record that stood until 2019, when 48 eruptions occurred; 2020 tied that figure. A new active phase began on March 15, 2018, and by February 27, 2026, 173 major eruptions had been recorded since its start.

The name comes from the steam locomotive-like roar of its eruptions, and the nearby Cistern Spring drains completely after each major outburst, refilling within a few days. Rangers post eruption reports at the Norris Museum, where visitors check the log of the 173 eruptions recorded since March 2018.

Access is provided via well-maintained wooden boardwalks that offer safe viewing positions at close range. Visitors should wear warm clothing and be prepared to wait at viewing areas, as eruptions are unpredictable and can happen at any time.

Cistern Spring, a short walk from Steamboat, drains completely after each major eruption and refills within a few days, so its water level tracks the geyser's activity. The two vents lie about 20 feet (6.1 m) apart, and the north vent throws the tallest columns. The highest measured jet reached 130 m.