Ain't it always his burros that won't march in line, stray off the trail, and smash their packs against the trees and the rocks? I wish they'd stray off far enough to fall down about 2000 foot of gorge.
10 seconds sound clip from the The Treasure of the Sierra Madre movie soundboard.
You can hear this line at 01:29:27.810 in the Blu-ray version of the movie.
Quote context
[...]
- Ha ha ha! See you in Durango.
- What was in your head when you offered to carry his goods for him if he couldn't manage by himself?
- He knew what he was doing when he turned them over to us.
- Mighty cute of him, wasn't it?
- What's the use of railing against the old man? It won't do any good.
[...]