In 2016, more than 120 National Park Service (NPS) units conducted BioBlitzes, supported by a collaboration between The National Geographic Society and the National Park Service. The Lawrence Hall of Science conducted an evaluation of participant and park outcomes at the cornerstone BioBlitz throughout the National Capital region, at the large (regional) Showcase BioBlitzes, and at additional events at National Parks across the US. The report includes a description of the evaluation project, case studies from 3 BioBlitzes, findings, recommendations, and the instruments used to measure