Using dynamite to excavate a bench mark hole.
Note dirt flying out of hole.
Level party of H. J. Oliver
Image ID: theb1791, NOAA's Historic Coast & Geodetic Survey (C&GS) Collection
Location: Northern California
Photo Date: 1932
Credit: C&GS Special Report Oliver 1932
• High Resolution Photo Available
of the U.S. Department of Commerce, National Oceanic & Atmospheric
NOAA Central Library
| NOAA Disclaimer
July 7, 2015