What was Harry distinctive hand gesture that imitated by john Wayne in the searchers?

The distinctive hand gesture you're referring to is not actually from "The Searchers" but from another classic Western film: "Stagecoach" (1939). In that film, John Wayne's character, Ringo Kid, uses a "thumbs up" gesture to indicate his approval or agreement.

This gesture became iconic and was imitated by many other actors in later Westerns, but it wasn't specifically connected to "The Searchers". It's worth noting that John Wayne was known for his iconic screen presence and gestures, and he often used variations of the "thumbs up" in other films as well.