I was playing a round at a local course here in MI when this happened. I overdrove one of the holes and when I went back in the bushes to look for it I heard a low growling sound no more than 25 feet away from me. I got my disc and got outta there. I was playing alone.
Two days later I went back to play by myself again and I heard the growling on a different hole. I looked to where the growling was coming from and saw a dark shape about hip height move out of sight. I was terrified at this point. I collected the discs I threw and left the one that was closest to the area where I saw the movement. The growling stopped but I was still getting out of there. The forest lines the left side of the fairway on this hole so I turned back around and started back up the hill towards the tee pad. I heard the growl again. This time from the top of the hill just to the right inside the forest. I stopped, turned left away from the forest and did a big loop around back to the parking lot.
This animal didn't growl at people in groups, just individuals. I haven't gone back for a solo round since I saw pictures of a Mountain Lion on a guys trail cam just on the other side of the disc golf course. The DNR came out and said there was nothing. One other person went out solo and heard the growling.
I have no idea if it's still there or not, but I'm not playing any solo rounds there anytime soon.