The Mary Louise Petersen papers date from 1947 to 1996 and measure 10 linear inches. The papers are arranged in nine series: Awards and diplomas, Board activities, Correspondence, Egyptian workshop, Magazines and programs, National Governors Association, Newspaper clippings, Speeches, Photographs and Artifacts.

The Board activities series (1971-1988) consists of a few miscellaneous papers from several boards on which Petersen served, including the Iowa State Board of Regents, Board of Directors and for the Carnegie Corporation.

The Correspondence series pertains mostly to her service to the Board of Regents. Letters are primarily from educators or legislators in the state of Iowa. There are, however, a few letters from friends.

The Egyptian workshop series (1981) consists of itineraries and programs from the workshop on "The Role of Regional Universities in the Rural Areas, which Petersen attended in Cairo, Egypt in May 1981.

The Magazines and programs series (1970-1986) includes articles about Petersen and programs from events Petersen attended for different organizations.

The National Governors Association series (1981) pertains to the associations 1981 meeting in Atlantic City, New Jersey. There, Petersen was one of eleven private citizens honored for distinguished service to state government.

The Speeches series (1970-1987) includes speeches given for the State Board of Regents and at conferences discussing education and trusteeship.

The Photographs series (1969-1980) shows Petersen receiving her award at the National Governors conference, speaking at a University of Northern Iowa commencement ceremony in 1983, and attending the rededication of the Old Capitol Building in Iowa City in 1976. Other photographs include Petersen speaking at Iowa State University during the rededication of the football stadium in 1975 and attending a campaign speech by Gerald Ford in 1976. Petersen is also shown in Guam and Taiwan, and with family and colleagues.