On April 22, 2021, GLOBE Observer published a peer-reviewed paper, “GLOBE Observer and the GO on a Trail Data Challenge: A Citizen Science Approach to Generating a Global Land Cover Land Use Reference Dataset” in Frontiers in Climate. The paper defines GLOBE Observer land cover data collection and quality assurance methods. Authors include members of the NESEC GLOBE Observer team, partners at the National Park Service and Geoscience Australia, and volunteer participants who collected significant amounts of data during the 2019 GO on a Trail data challenge.