The series consists of correspondence inward (with responses) to the director, assistant director, curators, and other personnel of the Provincial Museum. The correspondence is with collectors, amateur and professional naturalists, museum officials, and federal and provincial government departments and agencies and was created between 1897 and 1970.

The files include correspondence with the museum's first three directors (called "Curators" prior to 1913): John Fannin (1886-1904), Francis Kermode (1904-1940), and G. Clifford Carl (1940-1969). However, very little of the correspondence generated during Fannin's tenure has survived, while most of the Kermode files date from the post-1918 period.

The series also includes index cards created between 1925 and 1937 which records index details about letters in A-Z, and letters out, A-R.

Robert Brown (1842-1895) was a naturalist who took part in several expeditions and in 1864 he was appointed Commander of the Vancouver Island Exploring Expedition. The records consist of the journal and catalogue compiled while botanist for the British Columbia Botanical Expedition, 1863-66; journals kept as commander, Vancouver Island Exploring Expedition [VIEE], 1864-65; memoir on the geography of Vancouver Island, 1868; The land of the Hydahs, 1866; journals kept by A. Barnston, J. Buttle, T. Lewis, R. McDonald, J.Meade, F. Whymper during the VIEE in 1864 [vols. 1 and 2]; Vancouver Island Exploration Committee papers, including minute book, 1864-1865, correspondence, applications, bills and receipts, orders and reports issued by Brown; private correspondence, 1865-1895 [vol. 3]. Included in volumes 4 and 5 are transcripts of the VIEE journals, and some transcripts of Robert Brown's material. Two items were transferred to the BC Archives Library. A copy of volume 1, file 7 is catalogued as NWp 580 B862c ( previously NWp 581.9711 E96). A portion of the Catalogue of animals, plants, seeds, minerals collected by Robert Brown (from volume. 1, file 11), published in The Farmer, May 16, 1866 is catalogued as NWp 580 B862c. Both items were filmed by the Canadian Institute for Historical Microreproductions (CIHM no. 16844 and no. 16588 respectively). The originals could not be located as of October and August 2010. The Robert Brown records were microfilmed by the BC Archives in 1986. At that time, volume 1, files 7 and 9 were noted as missing.