This series consists of letterbooks of the Sheriff, the Under Sheriff, and subsequently the Comptroller General of Prisons (from 1891), containing copies of letters sent to Superintendents/gaolers, other prison officers and, occassionally, letters to prisoners. Some books also include copies of telegrams sent.
By 1898 some of the gaols already established in Queensland were: Brisbane, Toowoomba, Rockhampton, Roma, Mackay, Thursday Island, Fortitude Valley, Cooktown, Herberton,Blackall, Ingham, Ayr, Charters Towers, Normanton, Stewart's Creek, St Helena, Camooweal, etc.
All letterbooks (excluding the ones to St Helena and to Roma gaols) include an index at the front. The index gives the following information: folio/page number, letter number, to whom addressed, and brief subject. For each letter, the following details are included: the addressee and the sender, date, the letter number, the body of the letter, and signature.