Images

Moraines and glacial erratics (boulders) near Junction Butte in northeast Yellowstone National Park. Cosmogenic age dating of these erratics was used to determine when glaciers retreated from the Yellowstone Plateau.

A photo of a grassland area of eastern Wyoming taken for the Land Cover Trends project by Terry Sohl of the USGS.

Slow cooling of a basaltic lava flow that was erupted about 500,000 years ago resulted in the formation of hexagonal columns at Sheepeater Cliff, in Yellowstone National Park.

A 1.5-million-year-old basaltic lava flow in the canyon wall of the Yellowstone River as viewed from Calcite Springs Overlook near Tower Junction in Yellowstone National Park.  Slow cooling of this lava flow resulted in the formation of vertical columns.  Glacial gravels are present above and below the lava flow.

A burrowing owl amid grassland in eastern Wyoming is captured in a Land Cover Trends photo taken by Terry Sohl of the USGS Earth Resources Observation and Science (EROS) Center.

Water-quality sampling using a bridge crane on bridge crossing the Snake River at Moose, Grand Teton National Park

Dryland agriculture in the Northwestern Great Plains ecoregion.
 

Sagebrush-dominated ecoregions in the western United States (sagebrush cover types shown in various shades of yellow, pink, and blue-grey).

Benchmark T366, was installed in 1987 a few miles north of Canyon Junction in Yellowstone National Park. Rather than being a brass or aluminum disk, the benchmark is a rod that was driven into the ground until it would not sink any lower.  The precise elevation of the top of the rod was established by surveying methods, and an access cover flush with the g

Interpretive reconstruction of the Yellowstone Plateau region before initial plateau volcanism (a little before 2 million years ago). The region was entirely an elevated and faulted mountainous terrain with no basin in the present plateau area.

Boreal toad (Bufo boreas) mating ball, Bridger-Teton National Forest, Wyoming.

Geologic map of the Yellowstone Plateau Volcanic field generated by Bob Christiansen and published in 2001.  Available from https://pubs.usgs.gov/pp/pp729g/plate1.pdf.

Geological Map of the area around Monument Geyser Basin and Beryl Spring, taken from the Geological Map of the Yellowstone Plateau Area (Christiansen, 2001)

Left: Map of Yellowstone showing the extent of mapped Lava Creek Tuff members A and B, which erupted during the formation of Yellowstone Caldera about 631,000 years ago. Right: Geologic map of Madison Junction (1:125,000).

Yellowstone National Park employees Rick Hutchinson (right) and Jim Peaco (left) guide the specially designed Little Dipper boat into the boiling waters of Grand Prismatic Spring to collect measurements of the temperature and structure of the feature. National Park Service photo by Josh Robbins in 1996.

Queen's Laundry bathhouse, in the Lower Geyser Basin of Yellowstone National Park.  Building began under superintendent Philetus Norris in 1881 but was never finished.

Geologic map of the Wind River Range from Blackstone, 1993 (The Wind River Range, Wyoming: An Overview. Wyoming Geological Association. Jubilee Anniversary Field Conference Guidebook: Wyoming Geology, Past, Present, and Future. Pg. 121-140).

Fluid chemical geothermometer temperatures for Porkchop Geyser in Norris Geyser Basin, Yellowstone National Park, showing an increase of 40–60 °C (72–108 °F) for deep subsurface fluid temperatures near the time of the September 1989 Porkchop hydrothermal explosion.  Note the significant scatter and variations of estimates using the conventional geothermometers.&

Porkchop Geyser erupting in August 1989.

Ice cone at Porkchop Geyser in March 1989.

Apollinaris Spring in 1987.  The spring was modified in 1925 so that water would flow through pipes to be emitted from a rock wall.  Yellowstone National Park photo by Jim Peaco.