The typical underground coal mine in Korea is an extremely harsh environment for workers due to high temperature, humidity, and harmful dusts. In such environment, a remotely operated robot can be of great help to alleviate the work load of miners. As a joint effort, KAIST, Hydraumatics Co., and Korea Coal Corporation have developed a mining robot and a tele-operation system to operate the robot from a safe remote place. In this paper, we present the design of the robot mechanism and the sensing algorithms for localization and elevation mapping. The robot is hydraulically powered to drive the track and the cylinders in the excavation mechanism. The robot is equipped with two cameras, two laser scanners, and many other sensors so that the human operator can perform various tasks such as shoveling and breaking at a remotely located console. The data from various sensors are fused together to provide the human operators with enhanced visual cues as well as the pose information of the robot and its boom/arm/bucket linkage. The robot has been recently deployed in an active coal mine to evaluate its effectiveness in the real environment and demonstrated its feasibility as a viable aid to assist mining workers.