Author, A. A. (Year, Month Day). Title of map. [Description of map]. Name of Collection (Call number, Box number, File name or number, etc). Cal Poly Humboldt Library, Arcata, CA.
Author's Last Name, First Name (if given) or Name of Organization. Title of Map(if given). Map. Item # or Box/Folder # or Folder Name. Collection Name. Cal Poly Humboldt Library, Arcata, CA.
Author. Title of Map*. Title of Container, Other contributors, Version, Publisher, Publication Date, Cal Poly Humboldt Library, Arcata, California.
*Note: In some instances, your title of source will be in quotation marks as opposed to italics. Consult the MLA style guide for clarification.