United Air Lines Flight 105 Capt. Emil J. Smith, First Officer Ralph Stevens, Stewardess Marty Morrow who was called in by Smith as a confirming witness, flying northwest on heading 300° from Boise to Seattle at about 7,000 feet, saw five disc-shaped objects with flat bottoms and rough tops (possibly 100+ feet size) move at varying speeds, in loose formation, evenly spaced, roughly 1,000 feet higher in altitude about 10° left of their heading (or at 290°), with one high and to the right of the others in the distance, all disappearing to the west in a gradual climb at about 9:20 p.m. as five additional similar objects came into view slightly higher heading west. Smith tried to close on the objects at 185 mph as he climbed from 7,000 to 8,000 feet but could not.

One gray saucer was observed by three witnesses for under 12minutes (Smith, Emil J; Morrow, Marty; Stevens, Ralph).

Ruppelt's account:

That night a United Airlines crew flying near Emmett, Idaho, saw five. The pilot's report read:

Five "somethings," which were thin and smooth on the bottom and rough-appearing on top, were seen silhouetted against the sunset shortly after the plane took off from Boise at 8:04P.M. We saw them clearly. We followed them in a northeasterly direction for about 45 miles. They finally disappeared. We were unable to tell whether they outsped us or disintegrated. We can't say whether they were "smearlike," oval, or anything else but whatever they were they were not aircraft, clouds or smoke.

Google map of this location.