Click here for a picture.If you follow this link, the bottom right corner is that shooting spot. It looks like a clearing. The 'old' ranch is at the top left (by 'old' I mean that it has been there for many years). That is not a very big hill. You are shooting directly towards that ranch, and two or three more houses have been added since this picture was taken.
There are trails all over that area. There are a lot more now than when that picture was taken (the aerial I linked to, not yours). There are trails that go over the top of that hill from the other side. You can't possibly tell me that when you shoot there that nobody is going to ride up the back side; or that somebody riding up from the other side on an ATV is going to hear you through a helmet over the noise of their motorcycle. You can see in your pictures the road going over the top of the hill.
It's a bad spot to shoot, even if nobody has chased you off. There are better places at Table Mesa to shoot.