Image from the Biodiversity Heritage Library.
Contributed by Yale Peabody Museum of Natural History.
| www.biodiversitylibrary.org
Transcription
1950
Boulder County
no clay mines listed
Douglas County
Johnson Clay mine, at Castle Rock.
Stroud Wisenhunt
Castle Rock
" " both
plastic clay, 26,215 T
Helmer Mine at Littleton
Helmer Bros. R F Box 94 Littleton
Denver Sewer Pipe Co
4501 Fox St. Denver
fireclay: 1282 T
also: Helmer mine, same address
same people producing white sand,
limestone, & fire clay: 7697 fireclay.
Hogback Mine at Littleton
Robinson Brick Co
500 S. Santa Fe, Denver
same as above
plastic fire clay : amt not given