When the Visitors returned, they attacked the Ranch, in an attempt to capture Elizabeth, but the Red Dust killed them. They were far enough north, and up far enough in the Mountains that the Ranch is above the Frost Line.
The Ranch has become the Main Los Angeles Resistance Base, even if it is hours outside the city, as it provides them a secure location, and enough room to hold all the members of the Resistance.
Most of the Resident's of Onyx think the ranch is owned by Heather O'Leary, under the alias 'Heather Wilson'. She has upgraded many parts of the ranch with parts from her parents' ranch outside of College Station, Texas.
Updates to the Ranch include:
Two New Barns (one for Vehicle Storage, one as Living Quarters)
New Air Conditioning
New Hot Water Heaters
Underground Living Quarters
Hidden Closed Circuit Security Cameras
Underground Training Facility