I just watched the entire film, and had visions of being a child watching open-top front end loaders (or "diggers" as my brother and I called them) like in the movie.
What was most startling was seeing the near-empty interstate—comparatively speaking, our traffic today on nearly any road is at Soylent Green levels of congestion to the film's Oklahoma.
While I was aware of Brad-Penn Oil (Bradford, Pennsylvania) I was unaware that Kendall, "The Six Month Oil", had been derived from Pennsylvania oil fields. Thanks for posting this—truly cool to watch!