File:Ledge Geyser (afternoon, 2 August 2023) 1.jpg

English: Geysers are hot springs that episodically erupt columns of water. They occur in few places on Earth. The highest concentration of geysers anywhere is at the Yellowstone Hotspot Volcano (northwestern Wyoming, USA).

Ledge Geyser is the largest geyser in the Porcelain Basin of Yellowstone’s Norris Geyser Basin. It erupts infrequently to rarely, except for occasional years of relatively frequent activity (e.g., 1974, 2015). Its 2015 activity commenced in late March, after almost two years of dormancy. Thirty-five eruptions from Ledge Geyser have been reported between March and early November 2015. Eruptive activity in 2015 involved one to two hours of water-phase, followed by many hours of noisy, forceful steam phase. Ledge Geyser includes the “White Vent”, a prominent, light-colored geyserite shield covered in terracettes with a small, subtriangular-shaped hole. Ledge also includes the “Red Vent”, which is the current main vent - it has dark reddish-staining on its subvertical walls.

As of 2023, the "White Vent" is gray-colored. Ledge's activity now usually consists of noisy steaming and wet spray.