Series consists of records documenting Sadler's involvement in various naturalist and environmental initiatives with businesses, government bodies, and other organizations. Records document The Outdoorsman Magazine, Campbell Productions documentary films, the Design Canada Education Seminar and Workshop Program, the Ontario Department of Lands and Forests, the Provincial Wayside (Roadside) Conference (sponsored by the Otonabee Region Conservation Authority (ORCA) and The Federation of Ontario Naturalists) in Peterborough in 1965. Series also includes significant documentation on the Peterborough City/County Waste Management Study. Sadler was the chairman of the Public Liaison Committee that assisted with communication between the public and the Waste Management Steering Committee.

The collection consists of copies of photographic slides from holdings of the Archives of Ontario relating to Indigenous life in Ontario, North West Territories and Northern Canada.

This collection of photographs comes from the Library and Archives of Canada, Archives of Ontario, Saskatchewan Archives, Public Archives of Manitoba, Royal Ontario Museum and the American Museum of Natural History. Subjects include native peoples, immigrants, Riel Rebellion, surveys, and early explorers.

Fonds consists of correspondence, minutes, memos, publications, and financial and administrative records of the Canadian Parks and Wilderness Society. Also included are materials relating to campaigns, donors, etc.

This fonds consists of correspondence, reports, newspaper clippings and other material relating to several national parks in Canada. Also included is correspondence and reports relating to Parks Canada and Environment Canada, and NPPAC/CPAW's position papers, proposals, and newsletters. This fonds also contains miscellaneous brochures and pamphlets relating to parks.

File consists of photographs of the land Trent University's Symons Campus is now built upon. Many areas of the campus are captured including the river bank, the area of Lady Eaton College, many fields, and flat-land areas.

Subseries consists of photographs taken of the land acquired to build Trent University's Nassau Campus upon before construction began.

File consists of photographs of the land that Trent University's Symons Campus is now built upon. Most photos are of the flat lands to be built on or of the river, though some are taken from atop a hill looking down into campus, likely taken from what we now call the Drumlin by Lady Eaton College. Photos are glued to black cardstock.

File consists of photographs of the lands Trent University's Symons Campus is built on before construction started. There are many pictures of the river bank and what we now know as the Drumlin. Photographs were taken by F. McNamee

File consists of a photograph of Mala Naraine, Human Rights Advisor from 1993 to 1995.

File consists of two photographs Oleksandr Naida.

File consists of about ten photographs of George Nader, a Professor in the School of the Environment at Trent University.

File consists of a photograph of Dorothy Mutter, a former Trent University staff member.

File consists of two identical portraits of Dr. K.S.R. Murthy (d.2019) who was a professor at Trent University in the Department of Economics.

File consists of photographs of Noel Murphy (d.2017). He worked at Trent University from 1966 to 1999 he was the Chair of the Association of the Teaching Staff (A.T.S.) in 1982.

This fonds consists of various scripts and manuscripts, films, audio cassettes, etc., and related correspondence. Also included are photographs and personal correspondence.