Wildland fires can have significant impacts on air quality and contribute to detrimental effects on public health. Numerical models can be applied to simulate the transport and transformation of pollutants emitted during fires, providing valuable decision-making information. Frequently, air quality impacts extend from local scales into larger regional scales. It is therefore appropriate to simulate pollutant plumes from wildland fires using three-dimensional Eulerian grid chemical transport models capable of handling large scale emissions, meteorology, and physical processes. However, several limitations inherent to gridded regional-scale air quality models restrict the effectiveness with which plumes can be simulated using these modeling systems. EPA's Community Multi-scale Air Quality modeling system (CMAQ) is an extensively used chemical transport model. In this work, we have simulated the impacts of wildland fires on pollutant concentrations with CMAQ. Moreover, several techniques aimed at improved plume modeling were applied. Adaptive grid refinement was used in the simulations to overcome model limitations related to grid resolution constraints. Special emissions injection into CMAQ was also necessary to achieve realistic representation of wildland fire plumes. Additionally, fire emissions buoyancy, vertical layering adaptivity, and high resolution adaptive meteorological modeling were explored as strategies to enhance plume modeling. Model evaluation was accomplished by simulating fire episodes in the Southeastern U.S. from 2007 to 2009 covering different spatial scales. Pollutant measurements from monitoring networks were systematically compared to modeled concentrations to generate statistical performance indicators. Furthermore, evaluations were taken to a comprehensive diagnostic level. In-depth analysis and visualization of model processes and results were applied to determine the significance of different model processes, inputs, and sources of uncertainty towards successful plume simulation. The findings of this work provide insight into CMAQ's current ability to reproduce fire impacts and identify pressing research needs for successful simulation of biomass burning plumes with regional air quality models.