The Ontario Yellowbirds
In 1924, the government of Ontario set up a provincial air service to replace forest fire detection by canoe and foot patrols. Based at Sault Ste. Marie, the service's aircraft became know as the "Yellowbirds" because of their yellow and black colours. The Yellowbirds detected fire, transporting fire fighters and supplies and, from the 1950s on, pioneered the use of water bombers in battling wilderness blazes. Over the years the service also provided aerial support for mapping, wildlife management, regulatory compliance and other provincial programs. In performing so many functions across a vast territory, the Yellowbirds grew into one of the largest non-commercial air services in the world.
Plaque via Alan L. Brown's site Ontario Plaques. Full page here.