This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Core sections from the inch Calyx drill hole No. feet deep NARA .tif Scope and content Photograph from Volume Two of series of photo albums documenting the construction of the Grand Coulee Dam and related work on the Columbia Basin Project General notes Local identifier Department of the Interior Bureau of Reclamation Engineering