Cite

Map of the territory of Montana with portions of the adjoining territories / compiled and drawn by W.W. De Lacy, civil engineer & surveyor, Helena, M.T.

MLA

De Lacy, W. W. (Walter Washington), 1819-1892. Map of the territory of Montana with portions of the adjoining territories / compiled and drawn by W.W. De Lacy, civil engineer & surveyor, Helena, M.T.. BRBL_00579. 1878. https://collections.library.yale.edu/catalog/15814909.

APA, 6th edition

De Lacy, W. W. (Walter Washington), 1819-1892. (["BRBL_00579"])(1878)[Map of the territory of Montana with portions of the adjoining territories / compiled and drawn by W.W. De Lacy, civil engineer & surveyor, Helena, M.T.]. https://collections.library.yale.edu/catalog/15814909.