GIS and COS are unique codes to identify airports used in the aviation industry. They are defined by IATA (International Air Transport Association) and are commonly called IATA codes. GIS to COS refers to a flight route from Gisborne Airport to Colorado Springs Airport. This flight route has multiple associated airports, so we think it might be helpful to learn the name and codes of them as well. They are Denver Arapahoe Co Airport (APA), Pueblo Memorial Airport (PUB), Alamosa Airport (ALS).