is named for the shape of its pool, which is long (40 feet) but relatively narrow (10 feet), though the outline is not very evident from the trail as this stays quite far away - 100 feet - since this geyser is prone to vigorous eruptions, at intervals of between 3 and 12 hours. Water usually rises to around 25 feet, occasionally twice that, but the plume is wide and powerful; it is estimated that more water is produced during an eruption than for the much taller Old Faithful. Oblong Geyser sits right on the west bank of the Firehole River and most water drains directly into the channel but enough spreads in other directions to create extensive shallow pools, on terraces of sinter. It does sometimes enter a longer period of dormancy, when the surrounding pools become orange brown due to algae growth.
Back to map of the Upper Geyser Basin