Wildfire often amplifies the likelihood and magnitude of debris flows in steep terrain. In arid climates (e.g. US Mountain West and Southwest), post-fire debris flows typically occur during the first rains following fire, suggesting that rainfall-driven erosion is a strong control on in-channel preconditioning and triggering of these hazards. However, in the humid and forested steeplands of the Pacific Northwest, there is an apparent lag between cessation of burning and debris flow occurrence that suggests controls differ from drier climates. Preliminary results suggest that post-fire debris flows in Western Oregon are associated with the delayed triggering of shallow landslides and in-channel bed failures years after burning. David and Maryn are working to evaluate the spatiotemporal controls on post-fire debris-flow initiation and their impact on transportation infrastructure. Their respective research focuses on the physical characterization of root strength following wildfire and quantification of fire-related debris flow erosion relative to the long-term evolution of the Columbia River Gorge, OR.