Thomas Brock's first permit
By Volcano Hazards Program
1905 (approx.)
![Thomas Brock's first permit...](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/full_width/public/vhp_img6033.jpg?itok=Su52Ap8s)
Detailed Description
Thomas Brock's first permit to conduct research in Yellowstone National Park
Thomas Brock's first permit to conduct research in Yellowstone National Park