Like its sister collection, the May Swenson papers (COLL MSS 282), the May Swenson addendum has little or no original order left due to the piecemeal nature in which it was acquired. It was organized to mirror the order of the earlier collection, with three broad series containing the bulk of the manuscript materials: I. Personal, II. Professional, and III. Writings. A fourth series was added to accommodate a large number of audio recordings.

Series I contains family correspondence, autobiographical writings by Swenson, items pertaining to Swenson's death, and Zan Knudsen's notes for her Swenson biography. Series II contains professional correspondence, awards and honors, publicity, interviews and card files, as well as writing about Swenson and her work. Series III contains examples of Swenson's writings, mainly poems both published and unpublished. This series also contains poetry reviews written by Swenson, as well as music and poetry inspired by Swenson. Series IV consists almost exclusively of audio recordings. The first set of recordings includes reel-to-reel tapes that were numbered 1-58, probably by Swenson (note that 13 is missing). The last reel, Reel 59, was acquired from USU English professor Reed C. Stock, and is not a part of May's original audio collection. The CDs and cassette tapes appear to be copied from these reel-to-reel tapes.

While there is some original material in this collection, much of it consists of photocopies, either of material still held by the Literary Estate or from the May Swenson collection at Washington University in St. Louis. Written on documents throughout the collection are brief notes from Zan Knudson explaining the significance of the item. These notes provide useful context to researchers.

Conservation note: The reel-to-reel tapes were reboxed and foldered with the original boxes. Manuscript material found folded up in the original boxes was placed in a separate folder located just behind the reel from which it came.