• Visitors stand on the boardwalk of Grand Prismatic, the park's largest hot spring which is ringed with orange, brown and yellow runoff channels.

    Yellowstone

    National Park ID,MT,WY

Reports by Park Geologists

These reports are generated by park geologists. We began presenting them on the Website in March of 2004. Reports will be added as they are created.


The links that are labeled 'pdf' can only be viewed or printed using Adobe Acrobat Reader (available free, online).

Did You Know?

Seventh Cavalry Ensignia Pin.

Prior to the establishment of the National Park Service, the U.S. Army protected Yellowstone between 1886 and 1918. Fort Yellowstone was established at Mammoth Hot Springs for that purpose.