This reminds me. Since the FBI is involved, we can also assume they know to use Google analytics - which would track a fair number of cars as they traveled in the Monarch Pass area.
It would also reveal who, in the immediate vicinity, might be home with a wireless phone on, and whether the phone was stationary or being moved around. It would give a quick snapshot of the environment and of human activity over time (time of day when there are more cars on the road, etc).
The initial search warrant could have included getting such info from Google. And now that I think about it, I'm guessing that FBI has also traced, as far as possible, the positions of phones of people known to the Morphews, including any workers who may have been working alongside BLM.
You can add traffic cams to that list;. I believe there are two of them on the east slope of Monarch Pass. There is no wire or cable phone service, that I know of, and as I've posted twice now, only A,T&T and Verizon have cellular phone coverage on the east slope. A,T&T's is a cell that is mounted on a high mountain some distance away. Service is "spotty" due to obstruction of the other mountains. Verizon is reported by cell phone users to have good 4G coverage all the way up the east slope to the top, ON HIGHWAY 50. As I pointed out earlier, the Verizon cell is long and thin, aimed strictly to provide coverage on Highway 50. According the Verizon's own engineering drawings, coverage should be good at SM's house, but might be intermittent at her neighbor's.
Using cell phone coverage to locate people holding the phone gets dicey in the mountains. for example, let's guess that the neighbor's call to report SM missing went through the Verizon cell. Equipment would log the call, including the exact time, the duration of the call, and the line-of-sight distance from the tower. That can be plotted as an arc of a circle with the radius being the distance, and the arc being only as long as the width of the cell at that point. The actual cell is recorded, and LE can use the Verizon engineering. The accuracy is incredible, having a tolerance of plus or minus 15 ft (literally a 30 foot circle on the ground. Because the Monarch cell is pencil-thin, creating a very short arc, and the two houses are staggered distances away from the tower, LE could literally use cell data to verify whether the neighbor was at her house or SM's house when she called.
But let's imagine that the neighbor didn't know if the call was going to go through or not so she hopped in her car and started riding down the pass; looking for a cellular hot spot. If her phone "pinged" the A,T&T tower, she would have that hot spot, but due to the location of that tower, the tracking arc could be several miles long. They could say they heard car noise on her call, so she was on a road, and assume she was at the point where the arc crossed Highway 50.
What LE could not do, in this case, is plot where that neighbor was if she started hiking upward and connected with the A,T&T tower. Her phone may have pinged both A,T&T and Verizon during her walk, and they could plot her path looking for intersecting arcs. The one thing that LE can't do, in this situation, is triangulate exact positions..............simply because they only have two towers to work with.
All of this is totally my opinion. I welcome the posting of better explanations. IMO
