This is a very old promotional video from Kaiser/Willys Motors. The film apparently comes via Periscope Film, who makes old films available for licensing. (You can see many of their old documentaries in lower quality via YouTube; beware, a massive time sink awaits you there.)
It shows three early Jeep events: the 6th annual Jeepers Jamboree over the Sierra Mountains, a Jeep Rodeo (mud race) in Yakima, Washington, and a Jeep Derby (desert race) near Truth or Consequences in New Mexico.
Here is an article from Popular Mechanics covering the Derby, and one from Man’s Magazine about the Rodeo.
Doubtful you’ll ever see as many CJs in one place as you can in these films. Most were CJ-5s, but there were definitely a few flatfenders in there, including the winner of the Derby, a CJ-3B.
Perhaps the most interesting technical tidbit to me from the film was some Jeepers would disconnect their fan belts before a water crossing to avoid spraying more water into the engine. I’ve never heard of that technique.