Thinking about this further...
Apparently there is an old fire lookout atop Black Rock Mountain. It would be an interesting destination. Whether or not a person could hike up Black Rock Mountain on December 10 would depend on the weather that year. Usually one would not hike up there in December. At the very least a person would need cold weather gear, as it would be cold up there in December.
If one enters 'Black Rock Mountain' as their destination in google maps, the route shown in my previous post is what you get, down 30 Road, which is the road Jessica's car was allegedly found on. There is a trail on the west side of Black Rock Mountain, so google is not wrong. However, the preferred route up the mountain appears to be on the east side. That seems to be the ascent route most commonly used. In order to drive to that trailhead, Jessica should have turned off 30 Road at around the 10 mile mark, onto 35 Road.
So was she headed to Black Rock Mountain? It is hard to say. I really don't see anywhere else she could have been going. It is possible she was simply driving into the wilderness with no real destination in mind.
Given that Jessica ran out of gas, her disappearance could have been an accident. She may have become lost while trying to walk out. However, there are a number of ominous signs. Why was she headed into the wilderness in the first place? It sounds like she had no supplies. How is it that she got a flat tire? How is it that she ran out of gas? Why did she leave the key in the vehicle? She seems to have had a lot on her mind.
In determining what happened, it is fortunate she had a chance encounter with the kind folks who helped change her tire. Through that encounter, we know that Jessica was alone and in control. Foul play is unlikely.
It does sound like this is the area she reportedly went to with her daughter. "Police said Roggenkamp is familiar with the area where police found her car and had visited the same area on Thanksgiving Day." (
source) It would be very interesting to know precisely where she went on Thanksgiving Day. I'm sure her friends considered that when they searched for her.
Sadly, it is likely that a hunter or hiker will find her, eventually.