1930 - Present: The AZARNG was established on April 21, 1930 by Public Law 92 of the 71st Congress. The act served to abolish the Papago-Saguaro National Monument and reserve public lands for military purposes, specifically a rifle range. Since the congressional designation in 1930, PPMR has been an active military facility and rifle range. The current and historical activities at the facility include training and administration, aircraft fueling and maintenance activities, motor vehicle fueling and maintenance activities, fuel and solvent storage areas, gunnery ranges, detonation areas, and bunkers.

The PPMR mission has been consistent with training and administration since the facility was established in 1930. On-site training activities have, and continue to include: aircraft fueling and maintenance, motor vehicle fueling and maintenance activities, fuel and bunker storage areas. Several training and operational practices were discontinued in the past including solvent storage areas, gunnery ranges, detonation areas, and long-term storage of hazardous materials.

1946 - 1985: In 1946, a combined support maintenance shop (CSMS) (Building M5354) was established for the purpose of servicing and maintaining approximately 150 vehicles. Since that time, two more CSMSs have been established at the facility (Buildings M5340 and M5370). However, only Building M5370 currently continues to operate as a CSMS facility. In 1973 and 1985 operational maintenance shops #4 and #7, respectively, were established to service and maintain small vehicles. Both facilities remain as maintenance facilities. Based on the few records available and interviews with past and present employees, petroleum naphtha has historically been the primary solvent used. Limited quantities of trichloroethane (TCA) and chlorinated hydrocarbons have been used, primarily by the Army Aviation Support Facility (AASF) and wash racks. Prior to 1973, the AZARNG did not maintain purchase and use records for solvents. Throughout the history of the facility, numerous underground and above ground storage tanks have been used for storage of fuels, waste oil and solvents.

1950 - 1983: Prior to 1957, and on occasion through 1983, waste oils and solvents were spread on roadway surfaces as dust control agents. Beginning in 1983, with the exception of the above, waste oils and solvents have been collected in storage tanks and 55-gallon drums and turned over to the Defense Property Disposal Office at Luke Air Force Base for disposal, although during 1980 and 1981, waste oils and solvents at the AASF were collected in 55-gallon drums and disposed of by a private vendor. The AASF shop is reported to have had a 35-gallon solvent tank that was used for storing TCA. Additional historical information regarding waste disposal is not available.

The facility was connected to the City of Phoenix sanitary sewer in the mid-1950s. Prior to that time, a number of the facility operations, including maintenance and administrative offices, were serviced by septic systems and leach fields, which may have received hazardous waste substances. Reportedly, construction debris was buried on the site prior to 1992; however, there was no information indicating that other waste may have been buried on the property.

1985 - Present: Since the mid-1980s, numerous environmental investigations have been conducted at multiple PPMR locations for specific environmental concerns. Due to the age of the facility, earlier records are not available for many of the historical environmental practices. PPMR is currently a RCRA small quantity generator of hazardous waste, and generates various solid and universal wastes. The facility has not applied for a RCRA Part A or Part B treatment, storage and disposal facility permit. According to ADEQ, the facility has not received a notice of violation for noncompliance with environmental regulations.

2003: The Phase 3 Army Range inventory was completed at PPMR in May. The inventory identified one site as eligible for the MMRP. The Phase 3 inventory serves as the preliminary assessment under Comprehensive Environmental Response Compensation and Liability Act (CERCLA).

2004 - 2005: A site investigation began in May 2004 and was completed in fall 2005. An additional MMRP site was discovered during the site investigation that indicated the presence of contamination. Follow-up phases/actions were executed as required in the individual site cleanup strategies.

2010: An RI/FS work plan was submitted in May as per the recommendation of the site inspection conducted in 2005. In June, field work began at the site and the RI/FS draft report was submitted to ADEQ for review in September.

2011: ADEQ submitted comments on the RI/FS draft report, a final RI/FS and a proposed plan describing remedial actions were developed.

2012: Remedial activities moved forward at an underground storage tank release site.

2016: The second Five Year Review was completed and submitted to ADEQ for review.

2018: A Land Use Control Implementation Plan for Site S was submitted to ADEQ.

2020: The third Five Year Review is currently being prepared by the US Army National Guard and is currently scheduled to be submitted to ADEQ for review early 2021.