Naval Air Station (NAS) Dallas, located in Dallas, Texas, is an 810-acre facility that was closed in 1996 under the Base Realignment and Closure (BRAC) program. In order to transfer Navy-owned property to private and/or public entities, an extensive RFI/CMS is being conducted across the facility. The RFI/CMS is a joint effort between the Navy, the USEPA, the TNRCC, the cities of Grand Prairie and Dallas, and the Navy's subcontractor Tetra Tech NUS, Inc. During the RFI/CMS, a significant amount of electronic information has been collected. This information includes basemapping and chemical, geological, and hydrogeological data from over 1,200 sampling locations. As the RFI/CMS progressed, a challenge presented itself. How can nearly 2 GB of electronic information be made accessible to a wide variety of end users? To meet this challenge, the Navy implemented an ArcView GIS-based environmental information system. The main component of the NAS Dallas information system is an ArcView GIS project that stores output from a Visual FoxPro data management system. The ArcView GIS project spatially displays information for the entire facility through a unique combination of views, themes, scripts, hot links, customized buttons, and .apr files. The project also allows the user to instantaneously generate "tags" containing analytical data associated with any sample location at the facility. Ultimately, the ArcView GIS project became a building block for a much larger information system that encompasses alternative software applications. For example, an NAS Dallas Web page was created to transfer information between decision makers in distant locations. The Web page utilizes Esri's Internet Map Server to present the ArcView GIS project with highly customized interfaces and querying capabilities. The Web page also provides links to electronic documents and an analytical data querying interface. In addition to Web applications, ArcView GIS was combined with the Geosoft Geostatistics Package to contour contamination, EVS-NT Pro to produce three-dimensional visualizations of contamination, and Adobe Acrobat Exchange to generate electronic documents and layouts. The entire information system has been efficiently used for a wide variety of purposes. In particular, the system has been used to generate over 5,000 report figures, to conduct presentations during BCT and public meetings, to facilitate the transfer of information, and to assist in the decision making process. The purpose of this paper is to describe the structure of the environmental information system at NAS Dallas, provide examples of the system's end uses, and present the challenges that have been encountered along the way.