Geologist Ferdinand Hayden at work with a rock hammer in 1870
By Yellowstone Volcano Observatory
1870 (approx.)
![Geologist Ferdinand Hayden at work with a rock hammer in 1870](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/full_width/public/media/images/Hayden%20photo.jpg?itok=qx2l5FOv)
Detailed Description
Geologist Ferdinand Hayden at work with a rock hammer. USGS photo by William Henry Jackson, 1870.
Sources/Usage
Public Domain.