Cite

Route about April 20-30, 1805, and Lewis's route about August 7-10, 1806

MLA

Clark, William, 1770-1838. Route about April 20-30, 1805, and Lewis's route about August 7-10, 1806. Box 1, folder 22r. circa 1803-1810. https://collections.library.yale.edu/catalog/2002465.

APA, 6th edition

Clark, William, 1770-1838. (["Box 1, folder 22r"])(circa 1803-1810)[Route about April 20-30, 1805, and Lewis's route about August 7-10, 1806]. https://collections.library.yale.edu/catalog/2002465.