Robust monitoring of imperiled species is critical for developing effective forest management strategies and conserving biodiversity. The California spotted owl is a subspecies of conservation concern due to a combination of past land-use practices and emerging threats (e.g., large, high-severity fire), and is at the center of forest planning and restoration efforts. In 2021, we initiated a large-scale bioacoustics monitoring program—significantly expanding upon surveys conducted since 2017—by deploying ~1,600 autonomous recording units annually across the Sierra Nevada. We then leveraged a novel bioinformatics pipeline and machine learning algorithm (BirdNET) to detect spotted owl calls in >1 million hours of audio recordings. Here, we provide a summary of the first two years of the expanded monitoring program, with a focus on estimating spotted owl occupancy and evaluating the effects of high severity fire. Results from such monitoring and occupancy modeling efforts will be used to better inform spotted owl conservation and forest management practices, and can also be extended to derive estimates of population size. Overall, our research program demonstrates the feasibility of monitoring rare, vocalizing species over a large scale with bioacoustics, and in the long-term will enable us to study avian community responses to global change.