RETREAT (Retreating-trench, Extension, and Accretion Tectonics) is a multidisciplinary project to develop a self-consistent dynamic model of syn-convergent extension, using the northern Apennines, northern Italy, as a natural laboratory. This is a collaborative effort among Yale, University of Washington, Lehigh, Purdue, USC, SAO, and Italian colleagues. The GPS part of Project RETREAT measures crustal deformation associated with ongoing tectonic processes in northern Italy using a combined campaign and continuous GPS network. UNAVCO provided 10 new Trimble 5700 receivers and field engineering support for the initial campaign.