Guam Highway 12Guam Highway 12 is one of the primary automobile highways in the United States territory of Guam.Route descriptionGH-12 is a short connector route that runs eastward from Guam [Highway 2|GH-2] through the northern part of residential Agat towards the Ordnance Annex Naval facility in Santa [Rita, Guam|Santa Rita]. At the entrance, GH-12 turns north and connects to GH-5 running north then west.