Elevation: 7,300 ft.
Fan and Mortar Geysers are two geysers in the Upper Geyser Basin in Yellowstone National Park. These two geysers, for the past several decades, have always erupted in concert with one another and are generally talked about together. The records detailing these geysers' known eruptive history shows that they have been infrequent and irregular performers.
The two geysers lie right of the edge of the Firehole River. Fan and Mortar Geysers are easily viewed from both the bridge and the sidewalk directly leading north to Morning Glory Pool. This area is just a bit north from Riverside Geyser.
The two geysers lay on the edge of the Firehole River, just like Riverside Geyser. However, both of the geysers are on the same side of the river as the viewing area, unlike Riverside. Mortar consists of the large mortar-looking cone on the left. It consists of the vent in the cone, known as Upper Mortar, the vent right below it, known as Lower Mortar, as well as an additional smaller vent to the left of Lower Mortar.
Fan consists of at least 7 vents aligned roughly perpendicular to the river. They are known as (starting closest to the river), River Vent(s), High Vent, Gold Vent, Gold 2, Angle Vent, Main Vent, and the East Vent. A numerous assortment of other vents are scattered through the area, as well as one other geyser, close to the boardwalk, known as Spiteful Geyser.