Only Michael Bank's romantic gesture hit the rocks after he became stuck on his way down and had to be rescued.
The drama unfolded on the 600ft (180m) high Morro Rock off California's Central Coast.
The good news, his girlfriend said yes. The bad news, he now faces a hefty bill for his rescue.
A helicopter had to be called to help bring the 27-year-old back down to earth.
Police said he was later arrested on suspicion of possessing methamphetamine. Witnesses told reporters he was acting erratically.
"He couldn't go any direction, on a sheer ledge, with his feet dangling 80ft (25m) off the ground," Morro Bay fire Capt Todd Gailey said.
Climbing on Morro Rock is officially banned, though some people ignore the warnings. There have been several fatal falls over the years.
A US man aimed high when he decided to propose to his girlfriend - climbing a steep cliff face to pop the question via a video-app on his phone.