The frequency and magnitude of geomorphically-impactful events determine erosion and sediment evacuation rates that, when integrated over long timescales, define how landscapes evolve. However, little work has been conducted in "extinct" orogens like the southern Appalachians to quantify the landscape impact or return period of extreme events that likely dominate erosion and sediment transport in these ancient mountain systems. Climatic forcing drives bedrock incision, which sets the lower boundary condition on adjacent hillslopes in fluvially-dominated mountains and, thus, paces landscape evolution. From Sep. 26-29, 2024, precursor storms and the remnants of Hurricane Helene produced record precipitation over the southern Appalachians. In affected areas of NC and TN, ~300x normal flow resulted in significant bank erosion, bedrock incision, and the creation of new channels. Imbricated boulders, cobble terraces, gravels, and slackwater sediments deposited highlight the diversity of fluvial flow regimes at play during this event. This event initiated thousands of slope failures, including some of the highest volume and longest runout debris flows ever documented in the region. The fluvial system immediately mobilized most long-run-out slide sediment, as evidenced by a lack of debris flow fans in high-order channels. This event exposed previously unrecognized flood and debris fan deposits, offering a unique chance to quantity recurrence intervals of past extreme events. This incredible landscape modification, although devastating, provides a critical opportunity to understand how extreme events drive landscape evolution. Here, we present preliminary results of ongoing on-the-ground geomorphic surveying efforts of rapidly perishable data that started five days after the event. The surveys integrate ground, lidar, and photogrammetric analysis of fluvial channels, landslides, and debris flows in the Nolichucky, French Broad, Elk, and Watauga catchments to (1) establish catchment-averaged erosion magnitudes, (2) calculate discharge magnitudes to determine thresholds for considerable incision in this system, (3) quantify hillslope and fluvial erosion and deposition, and (4) identify key sites that may provide insight for the Holocene record of catastrophic flooding and debris flows.