Talk about an unlucky elk.

And a lucky lion.

The two got together Saturday in Custer State Park as a helicopter crew was shooting sedation darts at cow elk to drug them so they could be handled in a research project.

One elk hit by a dart staggered over into some vegetation to lie down.

It never got up, thanks to the lion, which was waiting nearby.

"It was a nice sunny day, and I guess that lion was sitting out there sunning itself when an elk staggers up and tips over," said Gary Brundige, resource manager in Custer State Park. "Well, what's any top-of-the-line predator going to do in a situation like that?"

It killed the elk and prepared to have dinner.

The action was over in a hurry. The helicopter crew made sure the elk was dead and moved on to the next one.

Crew members also reported that earlier in the day, they had seen what likely was the same lion in the area. It had briefly chased a group of elk that was being herded by the low-flying helicopter in preparation for darting.

"From talking to the pilot, it sounded like the lion gave a half-hearted effort to the chase," Brundige said.