An older gray-haired man, in a dark blue suit, drives to the edge of an unpaved road along the Grand Canyon, gets out, and, directly in front of his late-model yellow car, gazes over the canyon with his binoculars. While he is thus occupied, another man, younger and heavier set, sneakily walks up to the car, releases the brakes, and pushes it; his intent is to strike the older man and so that both he and his auto will plunge over the canyon. The car misses the well-dressed man who jumps out of the way. The younger man lunges for the older one but the ensuing quick struggle results in the victory for the older man. The younger one falls a long way to his death.
Right after we see Eli Jones (Tom Fadden) who fruitlessly tries to get the attention of deputy sheriff Les Martin (Cornel Wilde). Eli has seen the older man walking aimlessly (after the struggle), but Eli has previously "called wolf" once too often, so the sheriff dismisses him. Instead he chases after a fast driving young lady (Janice Kendon, played by Victoria Shaw) and gives her a speeding ticket. Later we find out that her brother Bob (Rian Garrick) is a drunk. Their father Jim (Alexander Lockwood) is an owner of the nearby Kendon mine. Meanwhile Eli returns to his office (the Kendon Mine Corporation), a remote frame structure. He sees the older man, the one in the dark blue suit, hanging from the ceiling with his hands tied behind his back. Sheriff Edwards (Edgar Buchanan) and Deputy Martin, who have been summoned by Eli, are on the scene of the crime. "Well, at least we know it's not a suicide," quips Edwards.
While Deputy Martin is investigating the case, he meets with guano mining foreman Bill Ward (Jack Elam), who tells him that his watchman, Charlie Piper, is missing. Martin discovers that the current mining operation (US Guano) involves 500,000 tons of bat guano (sold for fertilizer). A tram car supported by cable traverses 9,000 feet across the canyon. The expression "over the rim" had cropped up in Martin's investigation. The tram has something to do with something nefarious. At Scotty O'Brien's bar in town (Kendon), Martin gathers no information. A little more than a half-hour into the film, Martin and Bill Ward are being flown over the canyon where they spot a crashed yellow car and Charlie Piper's body. (Piper was the dude who tried to kill the older man at film's beginning.)
At the abandoned gold mine post Martin arrests a vagrant, Suds Reese. He has binoculars with the initials R.E.W. They are obviously not his; Reese claims he found them. But this comes to nothing. While Martin's investigation continues, his budding romance with Janice Kendon romance has amplified. One night at the Kendon Office Eli, alone, watches a TV show. A man, whom we do not see, enters. Through the man's eyes we observe Eli. Eli tells the man that he has spotted something of interest on the framed photograph hanging on a wall. It is Jim Kendon posing in a group photo next to the murdered man in the dark blue suit. Eli says that he will immediately call the sheriff. Thereupon the stranger takes a knife and stabs Eli to his death. Another murder!
The next scene focuses on a coroner's inquest that the politically minded county attorney is using for his own advantage. He is backing his own candidate for sheriff with the intention of removing both Edwards and Martin. The CA tries to rile up the citizen's committee. The coroner reminds the CA that the purpose of the inquest is to discover the identity of the dead man (blue suit) and the cause of his death. Because of the budding political situation over the unsolved three deaths, it is imperative that there is break in the case.
A break does occur about an hour into the feature. Deputy Martin discovers that the identity of the man in the blue suit was Randall E. Whitmore of New York, Executive Vice-President of Kendon Mining Corporation. Martin quickly drives out to the Kendon family home where all three family members (Jim, Bob, and Janice) happen to be present. Jim is genuinely shocked to discover that the dead man was Whitmore. And why was he out in Arizona instead of the NY offices? Martin surmises that Whitmore found out that someone was taking some of the gold from the Kendon mine without permission. Difficult, but can be done, says Jim Kendon. While this is transpiring Bob gets a telephone call and leaves. Janice, suspicious, says she will make a pot of coffee, and leaves the room. Instead of heading out into the kitchen, however, she takes her car and follows Bob to the local airstrip. At the airstrip things come together and we see the main bad guy, who comes as a surprise. I will not reveal his name. The movie climax occurs about 15 minutes later, and it involves a shootout on the suspended tram high above the Grand Canyon.
Using a USA National Park/Monument in movies goes back a long way. For instance, the first motion picture featuring aerial views of the Grand Canyon was a Tom Mix western, "Sky High" (1922). Yellow Sky (1948) was filmed at Death Valley National Monument (now Park). John Ford's beloved Monument Valley was the setting for many of his westerns, including "Stagecoach" (1939) and "The Searchers" (1956). Alfred Hitchcock used the Statue of Liberty National Memorial in "Saboteur" (1942) and Mt. Rushmore NM in "North by Northwest" (1959). In "Dangerous Mission" (1954) the star was Glacier National Park. "Close encounters of the Third Kind" (1977) featured Devil's Tower National Monument.
The cinematography is simply excellent. It must be also said that the acting is decent, even with Wilde's strange accent. Victoria Shaw looks great and for once Jack Elam is not the heavy. Entertaining and suspenseful!
