The sous-fonds consists of correspondence between the Lowrys and the Burts, the majority of which is from the 1950s and early 1970s, and audio-visual records of CBC programs, interviews, and celebration concert about Lowry and his works. This material is mostly from the early 1990s and 2000. Also included in the sous-fonds is Burt’s copy of Under the Volcano and notes regarding Under the Volcano in Lowry’s handwriting.