The Jean-Nickolaus Tretter Collection in Gay, Lesbian, Bisexual and Transgender Studies is a collection of LGBT historical materials housed in the Special Collections and Rare Books section of the University of Minnesota Libraries. It is located underground in the Elmer L. Andersen special collections facilities on the University of Minnesota's Minneapolis campus. The Tretter Collection houses over 40,000 items, making it the largest LGBT archive in the Upper Midwest and one of the largest GLBT history collections in the United States. The collection is international in scope and is varied in media.