From the Bowdoin University Digital Commons:
Between 2008 and 2011, the Bowdoin College Library conducted an oral history project to create a collection of spoken recollections and personal impressions from individuals who have known George J. Mitchell in a variety of ways. These oral histories document his life and career from early childhood onward, with particular emphasis on his public service to Maine and to the nation, and they complement his personal papers, which are also held by Bowdoin College.
Interviewees include Senator Mitchell’s Waterville (Maine) friends and acquaintances; family members; college classmates; Maine legislators; political associates and competitors; campaign supporters; U.S. Senate colleagues and staff members; public agency officials; foreign policy specialists; law practice associates; public policy advocates; board members of various affiliations; and friends.
You can listen to the interviews and also access the transcripts online.
Senator Mitchell is a 1954 graduate of Bowdoin College.