A national park in the Alligator River region was proposed as early as 1965 . In 1978 the Australian Government took over the titles of various pieces of land that now makes up Kakadu National Park . A national park in the Alligator River region was proposed as early as 1965 , but took until 1978 for the Australian Government to make arrangements to acquire the titles over various tracts of land that now constitute Kakadu National Park .