MLA

Clark, William, 1770-1838. Draft of the Great Falls and Dalles of Columbia River, route about October 22-29, 1805. Box 2, folder 50r. circa 1803-1810. https://collections.library.yale.edu/catalog/2002498.

APA, 6th edition

Clark, William, 1770-1838. (["Box 2, folder 50r"])(circa 1803-1810)[Draft of the Great Falls and Dalles of Columbia River, route about October 22-29, 1805]. https://collections.library.yale.edu/catalog/2002498.