I also live 5 minutes away if that, Rose Crest Subdivision. I was looking to build a home in Rose Canyon, and to my knowledge most if not all of that canyon is privately owned (not by one person). You can purchase anywhere from half an acre all the away up so 26 acre parcals (at least when I was looking for land last year about this time even.).
From what I was told while looking at property most of the land is privately owned and the rest is designated as open space (horse, hiking, no motorized vehicles). I was also told that if you venture onto one guys property he gets very angry and sends out his boys and calls in the law on you for tresspassing.
further up in and over the ridge is camp williams so I am thinking that the main road is all that you are really allowed on, unless you obtain written permission from the owner of the particular lot and/or parcal you are playing on.
I think it was sometime in February of this year they finally tore down that old round house that was attracting all the attention of the haunted house seekers (it was post on the inet with directions), and everyone in the area kept complaining about all the tresspasers as well as the traffic.
So I am doubting many are friendly to people just showing up and making their own trails etc.
I am contacting SL CO. about this to verify my posting of this message.