It All Points to Mount Rushmore
Hitchcock made a suave and colorful "small thriller" in 1955 with Cary Grant called "To Catch a Thief." For what it is -- glamourous(gorgeous Grace Kelly is gorgeous Grant's co-star), colorful(Oscar winning color cinematography of the French Riviera by night and day), and sophisticated(the dialogue)...it isn't much of a thriller, action or otherwise. There is some nice cliffhanging at the end(Cary literally has the upper hand against the villain) and a nice process shot car chase in the middle but...it is really a quiet , small non-thrilling thriller.
Not so, North by Northwest. Four years down the line at the very end of the fifties, with two masterful dramatic near flops just released(The Wrong Man and Vertigo), Hitchcock sensed that it was time to "turn up the volume" and make a thriller that really THRILLED. This would have not one, not two, but THREE action set-pieces(that's not so many as today but back then that was a lot) and the sense of a chase across much of America(well, two thirds maybe.) Just as Psycho would, one film later, "set the table" for shocks and slashing in thrillers(adding horror to the mix) North by Northwest rejected the sedate minor key mini-thrills of To Catch a Thief with something bigger, stronger, faster...better.
The opening action sequence is pretty good. The baddies have filled Cary Grant full of bourbon and put him behind the wheel of a Mercedes. They wish for him to drive off a cliff to his doom. But instead he crawls the car to the edge of the cliff, looks down at the crashing seas and rocks below him, and drunkenly steers the car on a "Mr. Toad's Wild Ride" down a curving road(mountainous is wrong for Long Island but...whatever.)
That's the first set piece in NXNW, near the beginning. The next set piece comes about midway through the film: the famous crop duster sequence in which about seven minutes of "nothing happening" (Cary waits by the side of an empty road in the middle of vast and empty prarie fields) gives way to about six minutes of exhilarating airplane dives at our hero and athlete runs by the hero, all ending with an explosive bang when a gas tanker truck meets the crop duster.
The "crop duster scene" seems to be the "artistic favorite" of critics who write on North by Northwest." Its absurdist construction. Its careful pacing and gradual acceleration into action. Its humor. Its great wide open spaces("Nowhere to run, nowhere to hide.") Its explosive finale(100 explosion-based thrillers start HERE.)
But Hitchcock has one more big set-piece up his sleeve. He saves it for the very end, and it can be said that the entire movie builds up to it. Cary had to survive the murder attempts via drunk driving and crop duster "all by his lonesome." He is given a companion for his final confronation with death: Eve Kendall, a woman he met two days earlier who he now realizes will be the love of his twice-divorced life, as long as he and she can survive being chased to and cornered upon: Mount Rushmore.
Hitchcock had wanted to stage a climax on Mount Rushmore for years, and likely realized he would only get it into a movie if an original screenplay could be written to get the story to go there. A chase across Mount Rushmore wasn't something that a spy novel would contemplate. It was a fantasy. Hitchcock said that the entirety of North by Northwest was a fantasy -- the crop duster attack is rather fanciful, yes? -- but the BIGGEST fantasy was to stage the climax on Mount Rushmore.
The predecessor in Hitchcock climaxes to this one, of course, was his Statue of Liberty climax in Saboteur(1942), But that statue didn't have much space for chasing on it. And Hitch elected to stage that climax not only with no music at all, but almost with no dialogue at all. It is a "silent sequence" accompanied only by the wind and a distant tug boat honk as the villain(not the hero) dangles from the outstretched hand of Lady Liberty and the hero tries to save him ...but alas, the villain is hanging by a thread and falls to his special effects death.
Hitchcock seems to have known that Mount Rushmore --a mountain , not a statue, consisting of four gigantic heads of four US Presidents -- would afford him much more room for action -- and much more need for some exciting, exhilarating, thunderous music (courtesy of Bernard Herrmann) to capture the chase.
Hitchcock said somewhere that "the Mount Rushmore sequence is the only reason I made the movie." He also said this about the shower scene in Psycho and the office rape-murder scene in Frenzy. Certainly the first two were classic for all time and the third ended up the most disturbing Hitchocck scene put on film.
But Mount Rushmore is the funnest.