The US Army’s Fort Irwin National Training Center (NTC), located in the west-central Mojave Desert of southeastern California, acquired 103,073 acres of land to provide additional space for maneuvers training of troops under simulated combat conditions. For its size, the NTC is the busiest installation in the Army. As part of its federal regulatory responsibilities, the Army needed to assess how its activities in the expansion area might affect important cultural resources. Far Western assisted the NTC with their Section 106 and Section 110 responsibilities. We inventoried 3,000 acres, evaluated 112 archaeological sites to determine their eligibility to the National Register of Historic Places, and carried out a geomorphological investigation to help interpret of the regional archaeological record. Far Western was subsequently hired to prepare a research design and work plan for data recovery excavations at 45 of the sites to mitigate potential adverse effects from the Army’s training activities.