Still from the production of the American silent western film <i><a href="https://en.wikipedia.org/wiki/Bob_Hampton_of_Placer" class="extiw" title="en:Bob Hampton of Placer">Bob Hampton of Placer</a></i> (1921) of a blimp used to film some scenes in Montana, on page 70 of the January 15, 1921 <i>Exhibitors Herald</i>.
Marshall Neilan Productions / Associated First National Pictures
1921-01-15
<a rel="nofollow" class="external text" href="https://archive.org/details/exhibitorsherald12exhi"><i>Exhibitors Herald</i> (Jan. - Mar. 1921)</a> on the Internet Archive