1986 Map of Lower Geyser Basin

About this map

The hydrothermal activity within Yellowstone National Park is documented in detail on this 1980s provisional survey of the Lower Geyser Basin. The landscape is dominated by the Firehole River as it winds through Firehole Canyon and across the broad Fountain Flats. Major thermal landmarks are captured during this era of monitoring, including the expansive Grand Prismatic Spring and the nearby Excelsior Geyser Crater in the Midway Geyser Basin. The map provides a precise layout of the Fountain Group, highlighting features like the Fountain Paint Pot and Celestine Pool. For researchers of the park's geological history, the sheet traces the intricate drainage of Tangled Creek and Nez Perce Creek, alongside numerous named vents like the White Dome Geyser and Great Fountain Geyser.