Horrible Today: Seconds of Big Eruption Geyser in Yellowstone Hot Spring Park Threatens Milions
Also at 100 Spring Plain is The Reservoir, a large, steady-flowing hot spring that was once used as a pool by park employees decades ago, when an earlier road network made the feature more accessible.
100 Spring Plain frequently floods, making travel dangerous most of the year, as one can’t tell where the shallow pools end and the deep, boiling thermal features begin (and it’s not without reason that there are so many thermal features scattered throughout 100 Spring Plain).
Other features at 100 Spring Plain with remarkable chemistry include Realgar Spring, so named in 1889–1891 by Arnold Hague for the arsenic sulfide (namely, the mineral realgar) that precipitates from the pool.
