This paper reviews the basics of GPS and GIS technology and describes their application for locating trees in rural park and forest settings. During a hazard tree survey in a Massachusetts state park, project members investigated the feasibility of using GPS and GIS to create maps that highlighted individual trees and other landmarks. The project intended to show that GPS and GIS can accurately locate trees. This technology is especially useful for arborists and urban foresters who need to map trees in rural parks, along rural roads and trails, and on large estates and institutional land, where other location methods are impractical. Depending on a variety of circumstances, GPS and GIS can be used in combination with aerial photographs or standard line and symbol maps to create appropriate tree maps for a particular area. Although certain problems still hinder the mapping process, new technology developments will expedite using GPS and GIS to produce maps.