The National Environmental Policy Act requires that Environmental Impact Assessments consider the cumulative effects of planned and reasonably foreseeable projects. As the result of a number of major projects planned for the Denver area over the next several decades, the Colorado Department of Transportation sought a methodology for conducting more systematic and effective assessment of their cumulative effects. This project involved collaboration with School of Engineering faculty. The Cultural Resources component involved the use of GIS-based methods for incorporating historical and archaeological resources in a broader environmental assessment.