For over a decade, we have been focusing on physics-based modeling of wildland and wildland-urban interface (WUI) fires. These are multiphysics events in which numerous physical and chemical processes, such as combustion, gravity-driven flows, turbulence, solid fuel pyrolysis, thermal radiation, and convective heating, interact with one another. We solve mathematical (differential) equations that capture these coupled processes and so describe the fire behavior using physics-based modeling. Because wildland and WUI fires have a wide range of time and three-dimensional scales, we do massive computations using parallel processing to resolve the scales with appropriate accuracy. We have had numerous projects funded by various federal agencies in the area of wildland and WUI fires.