late spring in yellowstone national park: spasmodic geyser erupts in the sawmill group in upper geyser basin

background basin blue caldera complex crater day environment erupts evergreen feature forest geology geothermal geyser green group hot hydrothermal landscape late national natural nature nps outdoor park pool sawmill scenery scenic spasmodic spray spring springtime steam thermal thermophile tourism travel trees upper vapor vent vents view volcano water wyoming yellowstone