This file ends at the Military Lease Area (MLA) boundaries, as the MLA is goverened by the DoD's Integrated Cultural Resources Management Plan (ICRMP). As of 12 May 2020, the current ICRMP is the 2015 edition, with discussions underway for a 2020 revision.

The Division of Historic Preservation does keep a Historical Property Inventory register of recorded sites within the CNMI. In 2019, HPO contracted for the creation of a digital (MS Access) database and geodatabase. As of 12 May 2020, population of those databases from paper files is still ongoing. Currently, no sites on Tinian have been digitized yet, beyond the NRHP and NHL boundaries.

In lieu of that statistical data, the current sensitive areas are drawn from institutional knowledge of areas that are known to contain or be likely to contain archeaologial or historical resources. Boundaries are heavily influenced by Alexander Spoehr's map of Tinian included as Figure 28 in his "Marianas Prehistory - Archaeological Survey and Excavations on Saipan, Tinian, and Rota." Areas along the Marpo Valley and along the bases of Carolina and Kastiyu Plateaus are also influenced by Bodner's 1993 and 1994 surveys for MPLC homesteads in those areas.