One of the principal goals of the Arizona Field Ornithologists (AZFO) since its founding more than 20 years ago has been to increase the knowledge of the changing status and distribution of Arizona's birds. It has particularly focused on learning about the seasonal distribution of birds in less familiar or more remote areas of the state. This note reviews what has been accomplished with the AZFO's eBirds Gap Project through 2025 and what steps are needed to continue filling in these gaps.