MLA

Kern, Edward Meyer, 1823-1863. "Sunday Oct 29 1848...before crossing Smoky Hill For[k]. Smoky Hills in the Distance." Watercolor drawing. Box 2, folder 18. [1848]. https://collections.library.yale.edu/catalog/2112308.

APA, 6th edition

Kern, Edward Meyer, 1823-1863. (["Box 2, folder 18"])([1848])["Sunday Oct 29 1848...before crossing Smoky Hill For[k]. Smoky Hills in the Distance." Watercolor drawing]. https://collections.library.yale.edu/catalog/2112308.