The ranches usually have large contiguous stretches of property, some up to 10 miles long on the border. Most of them are for beef cattle.
The entire run, I doubt it.
If you look at this map, there is about 10-12 miles west of Naco and you reach mountains that are federal property/forest service/BLM.
If you run to the east, there are mountains, they are probably owned by Phelps-Dodge and ranchers about 4-6 miles from Naco, then about 10 miles of flatland to Douglas AZ.
There is federal fence of old aircraft matting in Douglas proper.
Use the hybrid view.
http://www.google.com/maps?f=q&hl=en&q=naco+az&ie=UTF8&ll=31.342788,-110.106697&spn=0.128431,0.324097&t=h&om=1