Arizona Field Ornithologists (AZFO) is compiling up-to-date lists of bird species found in all of Arizona’s 15 counties. The Cochise County list, which has just recently been completed (AZFO 2023), includes 485 species of birds recorded to date, 86% of the Arizona state list (ABC 2022). The county, located at the southeast corner of the state, has a strong ornithological history, contributing many first U.S. records and at least 25 first state records. In the past 2 decades 30 species and many new breeding records have been added. This checklist serves as a reference for amateur birders and field ornithologists and as a record of the county’s avian natural history. It also provides a baseline for evaluating future changes to climate or habitat. This article describes the process for creating this checklist and highlights notable ornithological contributions of Cochise County.