In the fall of 2024, Hurricane Helene made landfall in the southeastern U.S., later downgrading to a tropical storm causing strong winds, flooding and major destruction throughout Appalachia. Now, researchers and public health officials in Environmental Science & Technology Letters provide a debrief about how their mapping of key locations, including private wells, septic systems and service facilities, helped distribute disaster relief in North Carolina—a part of Appalachia hit particularly hard by the hurricane.