Rescue Robots play an important role during rescue missions in disasters such as 9/11, which caused more than 2,000 deaths and thousands of injuries. However, tele-operating rescue robots are unable to perform their tasks constantly due to the limitation of current wireless communication technology. Therefore, rescue robots with the capability of performing their tasks autonomously during temporarily lost connections to the control base would be ideal. This paper introduces our development of a semi-autonomous rough terrain robot for rescue missions. The robot's hardware components, system architecture, and software architecture are described in order to provide a general overview of our robot. An alternative and comprehensive map-generating algorithm is presented and discussed. Finally, experimental setup and results from a testing arena are reported.Index Terms -rescue robot, rough terrain robot, semiautonomous robot, mobile robot, path planning, SLAM