The ROAMS rover simulator uses the SimScape tool for terrain models for rover simulations. Terrain data from orbital imagery has traditionally been of too low a resolution to be of much value for rover simulation. However this situation is changing rapidly with the availability of high resolution MRO HiRise data. This data is at 1m resolution which is close to the resolution needed for rover simulations. However, with the increased resolution comes the challenge of working with terrain models of significantly larger size. For instance, the Victoria Crater DEM at 1m resolution exceeds over 2 million grid points. This data set is large enough to tax the simulation and visualization capacities of even high-end workstations. Working with kilometer-scale orbital imagery based terrain data is required for simulating even moderate length traverses on Mars. Such terrain data sets are beyond ROAMS' current capabilities due to its data set size limitations. This task will extend ROAMS to handle realistic, high-resolution, and larger scale terrain models such as are becoming available from MRO HiRise imagery.