The U.S. Army Garrison, Hawaii is proposing to modernize the Pilila'au Army Recreation Center (PARC) on the Island of O'ahu, Hawaii. The proposed undertaking involves multiple related modernization projects, to occur in phases over several years, including rehabilitation of the current yard, construction of restrooms, installation of perimeter fencing, installation of an irrigation system, and general landscaping, and may be expanded to include operations, maintenance, and other activities, as determined in consultation. Buildings and structures on the campus have been evaluated and determined not eligible for the NRHP. The majority of PARC's property has been assigned a single archaeological site number (SIHP #50-80-07-3998) due to the homogeneity of the subsurface features identified there; however, there has not been extensive archaeological investigation of the entire site and some prior studies do not meet modern-day standards. Areas of prior disturbance and areas of low, medium, and high probability are not well defined, requiring additional documentation before implementing the undertaking to consolidate available information and assess the quality of prior data. USAG-HI initially proposed development of an MOA to govern the undertaking and the ACHP declined to participate (Case # 014215). During early consultation with the Hawaii SHPO, NHOs, and other consulting parties, however, USAG-HI determined that a PA would be a better tool for managing the anticipated long-term schedule of activities, with varying (phased) efforts for identification and treatment/management of historic properties, and contacted the ACHP to participate in the development of a project PA.