Alluvial fans offer a means to unravel the intricacies of landscape, tectonic, and climatic dynamics. This book and accompanying geologic map highlight alluvial fans and their deposits exemplified by a suite of debris-flow alluvial fans emanating from the Holocene-active western range front of the Sangre de Cristo Mountains in south-central Colorado. The link between morphologies of fan surfaces and the sedimentary facies of their deposits permits a basis for evolutionary process interpretation of debris-flow alluvial fan geomorphology. A grasp of these processes will help earth scientists better discern complexities between buried paleo-surfaces (intraformational progressive unconformities), surficial deformation, and landform development as recorded in debris-flow fan deposits in the sedimentary record.