Obviously, Vittorio and his renegade band just happened not to find this hidden valley.
5 seconds sound clip from the Hondo (1953) movie soundboard.
You can hear this line at 01:02:25 in the Blu-ray version of the movie.
Quote context
[...]
- Lieutenant, this here is Hondo Lane.
- He's scouted some and ridden dispatch some for the cavalry.
- I don't reckon I know this here lady.
- This is Ms. Lowe, Lieutenant.
- Obviously, Vittorio and his renegade band just happened not to find this hidden valley.
- And you lived? One lone man stood off Vittorio?
- No lone man stands off the Apache. He lets us live here.
- There are almost 100 dead settlers in the basin, scalped by this cowardly criminal.
- Vittorio may be a criminal by the books, I don't know.
[...]