"Eastern Portion Blackburn's Map of San Bernardino County" (San Bernardino, CA: Produced by O.V. Blackburn), undated, Sub-Series 1.4, Box: 22, Folder: 2. Collection of California maps and guidebooks, SC-012. Pfau Library Special Collections. https://archivesspace.csusb.edu//repositories/3/archival_objects/15212 Accessed January 09, 2026.