Denver Public Library has a wonderful collection of digitized photos and documents at http://digital.denverlibrary.org/cdm/search/searchterm/Bethesda, and below, I've digitized the photos we've had access to. Also, take a look at this amazing aerial map of Denver from 1933: https://www.arcgis.com/apps/mapviewer/index.html?layers=a9d5564d22da4bffaadf6b2bb2ec3960