I studied mountain lions for a year in college (they were going to be my study animal for my thesis, until it became clear that I wouldn't be seeing/handling many, if any, cats but lots and lots of poop); this looks to me like a juvenile mountain lion. First and second year cats are more likely to come to areas frequented by people, especially where water is available. After you set up some sort of security system, you should set out a big tray of wet sand near the pond, and see if you can get some tracks! Very nice wildlife cam shot!
