The data used here was collected as part of the Colorado Coordinated Campaign (C3). Field work was conducted in July and September 2021 in the Denver-Julesberg (DJ) basin in northeastern Colorado. The boundary of the study is shown in Figure S-1. C3 included aerial sampling coordinated with on-site measurement and extensive operational data collection. During the measurement period, partner operators were asked to record and report all maintenance events to the study team. The rst stage of reporting was done double-blind: Measurement teams did not know what events were reported, and operators did not know where aerial or ground teams identied emitters (SI section S-2). A second stage allowed operators to assess the timing of detected emissions to identify potential explanations for the emissions. This second stage resulted in identication of additional known maintenance and pre-production events.