MLA

De Werthern, H. Map of Utah and Colorado / Prepared by Order of Lieut. Genl. W.T. Sherman ; Drawn by H. De Werthern. s.n., 1869. https://collections.library.yale.edu/catalog/15818476.

APA, 6th edition

De Werthern, H. (1869). Map of Utah and Colorado / prepared by order of Lieut. Genl. W.T. Sherman ; drawn by H. De Werthern. [Maps]. s.n., https://collections.library.yale.edu/catalog/15818476.