Descriptions of the history of the Archaeometry Laboratory at the University of MissouriResearch Reactor and the procedures used for instrumental neutron activation analysis of archaeological materials are presented. The laboratory was established in 1988 to support students and faculty from the University of Missouri and other universities who were interested in archaeological research involving compositional analysis. The results obtained from the analysis of obsidian sources and artefacts from locations in the continental USA are presented for illustration.The proposal to build a research reactor on the University of Missouri (MU) campus was conceived in the late 1950s. The primary objectives were to stimulate scientific research and educational opportunities for MU faculty and students. Funds to build the reactor were appropriated by the Missouri State Legislature and approved by the Governor in 1959. Construction of the MU-Research Reactor (MURR) was completed and the reactor was in operation by the autumn of 1966. The choice of a flexible reactor design facilitated several expansions and upgrades over the years, to accommodate changing research needs and technological advances. Today, the MURR operates on a 150-hour per week schedule at a power of 10 MW and employs more than 140 full-time staff. The MURR supports research, education and service in a variety of disciplines, including (but not limited to) agriculture, engineering, medicine, epidemiology, chemistry, physics and archaeology.