The advantages of an unmanned ground vehicle (UGV) team include application of UGVs to a wider range of missions, reduced operator workload, and more efficient use of communications resources. Several mission applications for multiple UGV systems are described. Many single-UGV missions can be performed more quickly with a larger group of vehicles partitioning the workload. Certain missions, however, are possible only with a team of UGVs, or are greatly enhanced by cooperation among the vehicles. The four-vehicle surrogate semiautonomous vehicle system developed under the UGV/Demo II program is reviewed, and its capabilities for multi-vehicle operations are described. This system implements unmanned mobility, reconnaissance and surveillance, tactical communications, and mission planning and monitoring. The four semi- autonomous vehicles may work independently or as a team, controlled and monitored by a single operator. Ongoing development efforts for Demo II are described and longer-term directions for multiple UGV systems are presented.