The footage, as one would imagine, is very grainy and appears to have been shot by a crew member or someone that had access not given to the average person. It shows the preparations being put into the jump just moments before Knievel took flight.
Twin Falls is known for lots of things, one of them being the place that Evel Knieval failed to jump the Snake River Canyon in his rocket. Eddie Braun, another stunt man, decided to try the jump again decades later. Disney+ has created a documentary about the event featuring, of course, Twin Falls as well.