MLA

Office, United States. General Land. State of Colorado : Compiled from the Official Records of the General Land Office and Other Sources / Compiled and Drawn by H. Ruh. General Land Office, 1934. https://collections.library.yale.edu/catalog/15818428.

APA, 6th edition

Office, U. S. G. L. (1934). State of Colorado : compiled from the official records of the General Land Office and other sources / compiled and drawn by H. Ruh [Maps]. General Land Office, https://collections.library.yale.edu/catalog/15818428.