Cite This Item
MLA
Geological Survey (U.S.), and Illinois State Geological Survey. Base map of Illinois. Urbana, Ill.: The Survey, 1924. Web. 28 Jul 2025. <https://ark-dc3dev.bpl.org/ark:/50959/rn301202h>.
APA
Geological Survey (U.S.), & Illinois State Geological Survey. (1924). Base map of Illinois [Map]. Retrieved from https://ark-dc3dev.bpl.org/ark:/50959/rn301202h
Chicago
Geological Survey (U.S.), and Illinois State Geological Survey. "Base map of Illinois." Map. Urbana, Ill.: The Survey, 1924. Digital Commonwealth, https://ark-dc3dev.bpl.org/ark:/50959/rn301202h (accessed July 28, 2025).
Wikipedia
{{cite web | title=Base map of Illinois | website=DigitalCommonwealth.org | date=1924 | url=https://ark-dc3dev.bpl.org/ark:/50959/rn301202h | accessdate=July 28, 2025}}