Ron Crocombe's Cultural Map below, suggests there were once 3 Districts on Rarotongal. They are Avarua District, Takitumu District and Arorangi District
Apart from the initials J.H. bottom right corner, there are no dates or additional sources for validating what appears to be a cultural and soil-category map
This is not an offical map of Rarotonga
Updates would be posted as they become available
Source: Ron Crocombe Thesis 1961: Land Tenure in the Cook Islands