Which national park contains the Old Faithful geyser?

Which national park contains the Old Faithful geyser? Yellowstone National Park contains Old Faithful.

Old Faithful is one of Yellowstone’s most famous geothermal features, located in the park’s Upper Geyser Basin in Wyoming. It erupts because groundwater seeps deep underground, where heat from Yellowstone’s volcanic system turns it into pressurized steam. The pressure eventually forces hot water and steam through narrow underground passages and out of the geyser’s vent.

Despite its name, Old Faithful does not erupt at perfectly fixed intervals. Its eruptions are predictable because the interval since the previous eruption helps estimate the next one. Eruptions commonly last several minutes and send thousands of gallons of water high above the basin. The geyser was named by members of the 1870 Washburn–Langford–Doane Expedition, who were impressed by its regularity.

Old Faithful is not Yellowstone’s largest geyser; Steamboat Geyser produces taller eruptions. The name also does not mean every eruption is identical. Banff, Yosemite, and Grand Teton contain remarkable natural features, but Old Faithful is uniquely associated with Yellowstone.