The author details the deployment of three acoustical monitoring systems in April 2009 in Organ Pipe Cactus National Monument (ORPI). The purpose of this monitoring effort was to characterize existing sound levels and estimate natural ambient sound levels in these areas, as well as identify audible sound sources prior to the construction of several Department of Homeland Security Rapid Deployment Towers (RDT) that will be located on or adjacent to ORPI. Acoustical monitoring provides a scientific basis for assessing the current status of acoustic resources, identifying trends in resource conditions, quantifying impacts from other actions, assessing consistency with park management objectives and standards, and informing management decisions regarding desired future conditions.