Gray Line sightseeing bus, Seattle, Washington, circa 1951.
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/24256351@N04">Seattle Municipal Archives</a> from Seattle, WA
CC BY 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/seattlemunicipalarchives/49920045611/">Gray Line bus, circa 1951</a>