I’m always looking for dry spots to set cat traps. Today I found an old mine adit in the gully next to rocky ridge I was planning to set. About 15 feet deep drift and no pack rat middens in it which was surprising. Seems like a natural spot nonetheless. Anybody have any luck setting in the mouth of caves or mine adits? I usually look for overhanging ledges or rocks. Just wondered.

Looks great! Mountain lions MIGHT like it too....be prepared.
How are you going to anchor the trap? Can you stake outside...looks rocky.
Drag might cause issues if 'cat or lion goes into cave....thinking out loud.
Good luck.

Beware "no sign of pack rat middens" could be a warning sign.

I wouldn't set the mouth of the cave. I would set the trails leading to it on either side of the cave approach.Or what ever you can develop to block down a couple trails or more.

Like stated you could be dealing with a lion or two at some point or bears during your set up time there. Lots of wildlife that seek shelter or harborage will know about that cave as well. Better have a secure anchor point so you won't lose a catch that makes it to the cave.

If possible I bet a trail cam set on that hole would produce some good information.