Never Miss has it right. If you go in at Fly lake like I said earlier, park and walk to the rim. The rim rock is a good place to set up. Just down a bit so your not silhouetted. And watch your back those cats around there are not afraid of people.
The wind usually blows up or, down the canyon. And make sure your rifle is dialed in. My brother in-law made a shot well over 300 yd on a trophy buck but, thats another story. Chances are a guy could just sit there and not even call and have a crack at something.
I wish the family still had there place over there. I grew up with that area as my play ground back when you could still shoot on all common areas of Three Rivers. Have fun!