Conglomerate sedimentary rock, probably from Olympic National Park, date unknown

Chicago citation style
Walthal, G.. Conglomerate sedimentary rock, probably from Olympic National Park, date unknown. Retrieved from the Digital Public Library of America, http://cdm16786.contentdm.oclc.org/cdm/ref/collection/nps/id/1707. (Accessed October 17, 2018.)
APA citation style
Walthal, G., Conglomerate sedimentary rock, probably from Olympic National Park, date unknown. Retrieved from the Digital Public Library of America, http://cdm16786.contentdm.oclc.org/cdm/ref/collection/nps/id/1707
MLA citation style
Walthal, G.. Retrieved from the Digital Public Library of America <http://cdm16786.contentdm.oclc.org/cdm/ref/collection/nps/id/1707>.
Note: These citations are programmatically generated and may be incomplete.