Old Faithful Inn in the context of "Old Faithful"

Old Faithful is a cone geyser in Yellowstone National Park in Wyoming, United States. It was named in 1870 during the Washburn–Langford–Doane Expedition and was the first geyser in the park to be named. It is a highly predictable geothermal feature, erupting on average every 92 minutes, with the period between eruptions ranging from as short as 35 minutes to as long as 120 minutes. The geyser and the nearby Old Faithful Inn are part of the Old Faithful Historic District.

The Old Faithful Historic District in Yellowstone National Park comprises the built-up portion of the Upper Geyser Basin surrounding the Old Faithful Inn and Old Faithful Geyser. It includes the Old Faithful Inn, designed by Robert Reamer and is itself a National Historic Landmark, the upper and lower Hamilton's Stores, the Old Faithful Lodge, designed by Gilbert Stanley Underwood, the Old Faithful Snow Lodge, and a variety of supporting buildings. The Old Faithful Historic District itself lies on the 140-mile Grand Loop Road Historic District.

A notable missing portion of the district is the Old Faithful Museum of Thermal Activity, which formed part of the trailside museum group that includes the Madison Museum, Norris Museum and Fishing Bridge Museum, all listed as National Historic Landmarks. The Old Faithful Museum was torn down in 1971 to make way for the Mission 66 visitor center, which in turn has been replaced by the Old Faithful Visitor Education Center.