This information was emailed to me from an unknown and anonymous source. As the author isn't known, the authenticity cannot be verified. It is posted here for informational purposes only.
There can be a lot of activity at the south gate with people stopping and picture taking and checking out the views. This activity might make your vehicle blend in to the scene a bit better if you choose to park there. Consider a drop-off and pick-up scenario with a helpful driver as well. Whatever you do, check out the road and top of the South Butte with binoculars for any activity. You pass two signs on the road to the top. At the only fork in the road go left and the road ends at a tram. On the left side of the tram there is a use trail that goes to the buildings. Go pass the buildings (north) and you will see the true summit about 100 yards away. I was told that the most exposure you get to being seen is at the bottom near the start and end of road. Once you get up higher on the road you can easily move into bushes at side of the road and not be observed if you see a vehicle coming up or down. I was also told that even if there is activity at the towers you could bypass the buildings and get to the summit without being easily observed. Ideal times for an attempt might be major holidays, evenings and early mornings, and weekends. The view is supposed to be awesome.
The estimated time for roundtrip is about 3 hours at a moderate pace.