This data release is a field-verified inventory of postfire hydrologic response for the 2020 CZU Lightning Complex, River Fire, Camel Fire, and Dolan Fire following a 26-29 January 2021 atmospheric river storm sequence. Postfire hydrologic response types include a) no response, b) minor response, and c) major response. A “minor” response was deemed capable of impairing infrastructure functioning (e.g., deposition or erosion along a road that could be regraded by mechanized earth-moving equipment within a matter of hours) or causing minor bodily injury (e.g., abrasions, sprains, or broken bones). A “major” response was deemed capable of causing sustained infrastructure impairment (e.g., damage to roads requiring weeks or more of emergency repair efforts or residential structures made uninhabitable) or serious bodily injury (e.g., protracted disfigurement or death). The README.txt file describes the data fields for the “Inventory.csv” file. Fields with value “-9999” indicate that data are not available or do not exist.