Collection consists chiefly of an album of photographs and clippings compiled by Cecile (Burroughs) Masson. Captions date the photographs to between 1915 and 1940, with one earlier photograph from 1883 that depicts Cecile and Rodrigue Masson's wedding. Many of the personal photographs depict members of the Masson family taken in Terrebonne, Quebec (where the Masson family home was located), in Ottawa, and during travels to Italy, London, the south of France. There are 28 leaves of full page plates of travel photographs from France, Italy, and Africa. Also included in the album are postcards and newspaper clippings. One series of postcards depicts architecture in Terrebonne, Quebec. The clippings include a letter to the editor written by L. R. Masson (Mrs. L. A. Globensky) and published in the Montreal Star, 1939. Other clippings relate to the S-Plan, a bombing campaign by the Ireland Republic Army, in 1939, as well as the British royal family. The album is half bound in faux black morocco and pebbled cloth boards with the initials C. M. stamped in gilt on the front cover. A caption at the head of the second leaf reads "This album is for mother from Grace", with "mother" crossed out. An inscription on the first leaf reads "This is for my dear daughter Cecile. Many happy memories of the past - affectionately from Mother." The collection also includes two loose black and white photograph portraits, one of which is inscribed to Aunt Cecile.

The collection consists of documents amassed by Roderick Mackenzie. Among the Masson manuscripts there are other series of letters; as well as journals kept by North-Westers and various business documents. Some of this material exists as originals; others are contemporary copies - the George Keith letters for example are contemporary copies on paper watermarked 1827. The collection also includes some duplicate texts - contemporary copies or later nineteenth-century copies that in some cases represent edited versions of the texts. Samuel Wilcocke's account of the death of Benjamin Frobisher exists in a draft original (or contemporary copy) and in a late nineteenth-century clean copy. Of course Benjamin Frobisher did not die in the dramatic circumstances as recorded by Wilcocke, but peacefully in Quebec City in 1821.