The Osiris Collection, 1972-2021, contains material related to the editorial and production business of the magazine, as well as the personal poetry career of Andrea Moorhead. The issues with production material start with issue 26 and span to issue 76, with some issues missing in the earlier years. The bulk of the material is correspondence, organized alphabetically, ranging from 1970-2012, with electronic mail at the end of the series. Electronic mail has been left in original order, organized in groups by country or language. Some correspondents of note include Anne Blonstein, Christian Arjonilla, Jean-Chapdelaine Gagnon, Philippe Haeck, Robert L. Lepper, Oliver Mechcatie, Harold Norse, Lyn Lifshin, Raymond Federman, James Laughlin, Charles Hadfield, Nicole Brossard, and Simon Perchik. Business records include subscription renewals and invoices from mostly library subscriptions.

The Andrea Moorhead series consists of her manuscript drafts organized in chronological order in five large notebooks. Also included are some theater draft material; French serials including Moorhead's photographs; and poetry career correspondence which includes acceptance letters for her poetry and reviews, and other professional acknowledgements. Accruals from 2021 include production and correspondence materials related to issue 87 and 88, as well as reviews dating from circa 1983-2003.