Trail map for Yellowstone National Park
21 views of the Crater Hills; gallery
VideoBison and thermal features
(mp4; 2:08 min; 40 mb).
The best place to park for a trip to the Crater Hills is at the southernmost of four pull-outs on the east side of the highway close to the Yellowstone River, just south of Hayden Valley. Owing to the plentiful bison, this area is often very busy, and vehicle jams form when the animals walk across the road. This part of the river valley is bordered on the west side by steep hillsides that hide the springs and the grasslands beyond, but these soon come into view after a short walk up the hills to a ridgetop, over ground crossed by many bison trails. If the bison are in residence then a diversion will be needed, but if not then the springs are reached by hiking due west for a mile, down the far side of the ridge, across a shallow valley and through a thin belt of fire-damaged woodland.
The Sulphur Springs
are found on the south side of a prominent rocky summit, which is wooded on top but overlooks a big expanse of white earth nearly half a mile across containing about 70 recognized thermal features, ranging from small vents to a deep boiling pool 25 feet in diameter (Crater Hills Geyser, aka Sulphur Spring). The section closest to the road is at the southeast edge of the basin, and has scattered small vents, variously-sized mud pots and a few large pools filled by bubbling, viscous, brownish-grey water, all surrounded by mud flats. To the southwest, on the far side of a narrow, partly wooded ridge, is a shallow ravine through dry mud hills, with more mud pots, hissing vents and unstable ground, and two named features - Alice Springs
and Turbid Blue Mud Spring
; the former is a cloudy, boiling spring edged by yellow sulphur deposits, the latter a bubbling, metallic grey pool.
Crater Hills Geyser
The best group of springs is further north and extends to the edge of the hills, formed by a steep, rocky slope of jagged, whitish rocks in between which are scattered, fierce-sounding gas vents. Below are a variety of hot pools, generally filled with clear or translucent water unlike the cloudy, viscous pools lower down, plus several beautiful springs with unexpectedly bright colors including a lime-green pool, a green pool with red vents, and a tiny opening producing clear water on top of black, red and orange mineral deposits. Some vents are dry but instead emit sulphur-laden gases that condense to form pure yellow crystals. Crater Hills Geyser
is the single most impressive feature - a deep, fiercely boiling pool of turquoise-blue water surrounded by extensive depositional sinter formations and shallow pools, like a coral reef at low tide.