The Disney animated short, Bearly Asleep, was released in 1955 and features Donald Duck as a park ranger (bottom right image).
After the tourists go for the winter, he makes sure the bears hibernate but Humphrey keeps snoring and they throw him out of the cave.
He tries to trick his way into Donald’s house and in the end the duck disguises the bear as a baby and he’s welcomed back by the hibernating bears.
Movie pages here.