Cite

Route about April 14-23, 1805, and Lewis's route about August 10-12, 1806

MLA

Clark, William, 1770-1838. Route about April 14-23, 1805, and Lewis's route about August 10-12, 1806. Box 1, folder 21v. circa 1803-1810. https://collections.library.yale.edu/catalog/2002464.

APA, 6th edition

Clark, William, 1770-1838. (["Box 1, folder 21v"])(circa 1803-1810)[Route about April 14-23, 1805, and Lewis's route about August 10-12, 1806]. https://collections.library.yale.edu/catalog/2002464.