Bridge being demolished
This is a frame from the movie "The General" showing the moment the bridge was destroyed. It is at 1:05:28 in the YouTube copy of the film.
Frame from movie; the movie is in the Public Domain
BH Photo #324654
It is called "the Rock River bridge" at 33:09 and 57:56 in the movie.
This bridge was built for the film and was not a bridge used by the Oregon Southern and Eastern Railroad itself. It was designed to collapse at the climatic moment of the film, so bridge affectionados can relax - no real bridge was harmed during the making of this movie!
Of more interest is the over-under trestle shown part way through the movie in the scene where the raiders, on the top level of the trestle, throw ties down onto the train passing below in hopes of derailing it. There were only three or four known Over and Under Trestles in Oregon, and most of them don't match the setting in the movie - and none of them were anywhere near Cottage Grove, where the film was made. For years railroad fans and film nuts have wondered where that particular scene had been shot.
Lloyd Palmer, Terry Gookin, Len Wall and a group of several other rail historians and fans, myself included, finally located photos of an over-under trestle at Black Rock, Oregon, west of Dallas that match the trestle in the movie exactly, and given that the logging railroad at Black Rock was owned by George Gerlinger, and that Buster Keaton had sent the locomotives to be used in the movie to Gerlinger Locomotive Works to be refurbished and back-dated for the film, we knew that the movie engines had been in the vicinity, and personal examination of the trestle site and comparing it with both historic photos of the trestle and stills of the movie proved beyond a shadow of a doubt that the over-under trestle scene was filmed at Black Rock.
By the way, the Oregon Southern and Eastern Railroad, and its trestles, featured prominently in another film - Emperor of the North - starring Lee Marvin and Ernest Borgnine. It's a pretty dreadful and violent film, the only saving grace is that it also contains some of the best steam railroad action scenes to ever grace the silver screen.