Though not required of public domain images, if you want to credit the library as the source, please use the following statement: "From the San Francisco History Center, San Francisco Public Library" and provide a link back to the item on our Digital Collections site.
Rights Statement
In public domain.
Note
"Crystal Springs By-Pass Tunnel Construction, Interior of Crystal Springs Shaft, Drilling at Heading" Image #M-15-3 Photographer: Ken Snodgrass