The Wilson Popenoe papers were given to the Archives of the Hunt Institute in 1976 by his son, Dr. Hugh Popenoe.

The first section of the collection, Correspondence, includes not only letters to and from Wilson Popenoe during his lifetime but also other family correspondence. These letters cover nearly 100 years of Popenoe correspondence.

The second section consists of Subject Files used by Popenoe for his own reference, which include letters, published and unpublished manuscripts and writings, field notebooks, photographs, reprints and newspaper articles, as well as documentation and most of the published newsletters from the Escuela Agricola Panamericana.