Burlington Northern Santa Fe Railroad (BNSF) operates 1,300 trains across a rail network encompassing 31,000 miles. In order to respond to emergency situations quickly and effectively, trains, facilities, and people must be located, identified, and notified in near real time. GIS is well suited to providing the information that decision makers and emergency planners need. However, facilities and equipment spread across two-thirds of the United States present some unique technical challenges. BNSF's Network Operation Center (NOC) requires applications that allow rapid retrieval and display of massive amounts of geographic data, an easy-to-use multiuser interface for scenario management, integration of BNSF's linearly referenced data into the GIS, and a fault-tolerant client/server available 24 hours a day, seven days a week. SDE on an Oracle database server was implemented for rapid database access, and ArcView GIS extensions on Windows NT clients were developed to produce maps and reports to support emergency response management. Incident management maps can be projected on 216-foot-wide nine-screen display at BNSF's NOC to assist BNSF personnel in coordinating incident response. The development of the SDE database provides the foundation for integrating GIS applications for other BNSF business processes.