The Robotics for Engineer Operations (REO) project is a Science and Technology (S&T) effort led by the U.S. Army Engineer Research and Development Center. Its goal is to provide increased survivability of U.S. Army Engineers by removing soldiers out of high-risk operations while also expanding capability and capacity to support construction engineering operations. For this end, REO proposes a multi-robot system as a viable mechanism to remove the Combat Engineer from danger. The proposed multi-robot system consists of a fleet of autonomous mapping and site characterization platforms, along with autonomous construction equipment with a human-in-the-loop. These platforms are equipped with a range of sensor modalities, computational systems, and military-grade radios, enabling them to operate effectively in undefined and uncontrolled environments without relying on Global Navigation Satellite System (GNSS) positioning. With this system, Combat Engineers can conduct reconnaissance and perform construction engineering tasks from a safe standoff position, often in Beyond Visual Line-of-Sight (BVLOS) conditions. This allows them to complete critical tasks without the need to physically enter high-risk areas. The robotic system enables these standoff capabilities through BVLOS teleoperation and autonomous tool operations of commercial off-the-shelf heavy construction equipment and Army Small Multipurpose Equipment Transport (S-MET) platforms, providing increased operational capacity and efficiency. Additionally, the REO system delivers autonomous site characterization capabilities, creating a detailed 3D model of the environment using a multi-modal sensing approach. This model helps engineers understand the site and identify key features, supporting mission planning and task execution. The mission planner consolidates information from satellite imagery, the 3D site model, available assets, and mission requirements into an interactive 3D environment, accessible through the Android Tactical Assault Kit (ATAK). This integration of technologies supports current Army operations and has the potential to expand into future areas such as disaster response, infrastructure construction, and other civil works applications.