Arranged in 11 series:

Series I. Correspondence, 1927-1968. This series consists largely of letters written by Elarth to her mother while traveling and studying in Europe in 1927-1928. In addition to the usual descriptions of activities and sights, Elarth comments at length on the art and architecture that she sees. Among the places from which Elarth writes are London, Paris, Florence, Rome, and Athens. The series also contains a small folder of correspondence received by Elarth from friends and family.

Series II. Diaries, 1927-1968. Elarth's diaries commence with her stay in Europe in 1927-1928. In brief entries, she records travels, personal activities, studies, books read, work, health, and weather conditions. Elarth favored five-year diaries, containing pages formatted to hold entries for five successive years of a given day/month. With few exceptions, Elarth made daily entries, providing a nearly continuous record of her activities for 40 years.

Series III. Life and Career, 1905-1971. This series contains materials relating to Elarth's personal, educational, and professional activities. Included are files relating to her birth and marriage; education; employment history; activities in clubs and professional organizations (particularly the American Association of University Women); and personal interests. The files contain correspondence, notes, and printed material. A folder of personal mementos includes address books, identification cards (including a card and bookplates for Hendrik van Ingen), a few pieces of unattributed poetry, and notes made by Elarth on the provenance of a few family heirlooms.

Series IV. Van Ingen Family, 1873-1967. This small series contains materials relating to Wilhelmina van Ingen Elarth's paternal family. Included is a folder of correspondence containing four letters addressed to Minnie van Ingen. Also included are mementos from the wedding of Hendrik van Ingen and Ethel Mae Bell, a small collection of legal documents, and papers relating to the estate of Josephine van Ingen.

Series V. Postcards, ca. 1932-1968. Elarth's substantial collection of postcards focuses largely on the art and architecture she encountered during travels in the United States, Mexico, Europe, and other places. The postcards seem likely to have been assembled to assist in art instruction, with particular emphasis given to the United States, Mexico, Greece, and Italy. The majority of the postcards are unused. Arranged by continent, then nation, then locale and/or medium. Large-format postcards are filed at the end of the series.

Series VI. Printed Material, 1928-1961. This series consists largely of guidebooks likely used by Elarth during her travels in Mexico and Europe. Also included is a folder of assorted printed materials consisting of play programs, scholarly articles on ancient artifacts, and reproductions of various pieces of art.

Series VII. Artwork, 1883-1957. Contained in this series are original works of art created by Wilhelmina van Ingen Elarth and her father, Hendrik van Ingen. Included is a collection of greeting cards designed by Elarth, consisting mostly of Christmas cards, many of which are thematically based on the art and architecture of ancient Greece. The series also contains a set of pencil and watercolor studies completed by Elarth. Also in the series are a sketchbook and a collection of unbound sketches signed "HVI" and attributed to Elarth's grandfather, Henry van Ingen. Van Ingen's sketches portray scenes from New York state, focusing particularly on the areas of Poughkeepsie and Seneca Lake. Completing the series is a small collection of artwork by unidentified artists, including silhouettes of Hendrik van Ingen and an unidentified woman, as well as five Japanese watercolors.

Series VIII. Artifacts, n.d. This series contains Elarth's collection of ancient Aegean and pre-Columbian pottery, clay, and stone artifacts. Included are surface-found pottery and clay shards from various Greek and Greco-Roman sites on the Greek mainland and the Aegean Islands. Few of these shards are larger than 5 cm. in length. The collection is arranged by the numbers Elarth assigned to each piece, though the key to the numbers seems to have been lost. A few unnumbered pieces are arranged at the end of the set. Included are three fragments of a small vessel (82.10), a broken but restored phiale (82.37), a lamp (82.46), a Spartan marble fragment (82.51), a black-figure vessel lid (82.52), and three unnumbered items: a partially restored goblet with human figures in bas-relief, a clay spindle whorl, and a broken Minoan box lid with relief handle of reclining dog.

Also in the collection are pre-Columbian artifacts either surface-found or purchased by Elarth at the Huexotla site near Texcoco, Mexico. The pieces date from the Toltec/Aztec occupation, after ca. 1000 CE. Included are 22 small earthenware shards (few larger than 5 cm. in length), some with orange slip and additional decoration; others, undecorated. Also included are four clay head figures (three human, one animal) and six clay spindle whorls with stamped decoration. The collection also contains six pieces of carved stone artifacts: a miniature obsidian skull, a miniature jadeite mask, a carved relief of uncertain purpose, and three fragments of worked obsidian.

Series IX. Heirlooms and Mementos, 1862-ca. 1940. Elarth's activities and interests are represented in this collection of objects. Included are pieces of jewelry, insignia pins, souvenirs from world's fair expositions, small collections of sealing wax impressions and Susquehanna Valley Bank notes, an ornate carved wood (19th century Dutch?) smoking pipe, and various personal effects. Many of the items likely belonged to Elarth's parents and husband. Also included is what appears to be a large (32 cm. diameter) Native American (perhaps Navajo) pottery bowl, broken into 33 individual pieces ranging in size from tiny to large.

Series X. Photographs and Negatives, 1893-1967. These photographs chronicle Elarth's life, family, friends, and travels. Included are photographs of her Newton, Bell, and van Ingen ancestors, with individual files devoted to her mother and father. (Included in the Hendrik van Ingen file are a number of photographs of buildings under construction, likely being homes that he had designed.) Also included in the series are photos of the Elarths and family friends. A number of other photos in the series, showing scenes of the Rochester and Poughkeepsie, New York areas, were probably taken or collected by Hendrik van Ingen. The Elarths' home in Manitoba, Canada is shown in several dozen photos. The series also contains a large number of negatives, the majority of which are from Elarth's time in Greece. Also among the negatives are images of family and friends; travels; and the Elarths' homes in Manitoba and Virginia. Many of the negatives in the series have no corresponding print.

Series XI. Photo Albums, 1905-1927. The collection's albums largely mirror the photos found in the previous series. Included are two albums likely compiled by Hendrik van Ingen, containing photographs of various scenes, probably in the areas of Poughkeepsie and Rochester, New York. Also included is an album containing photographs of Wilhelmina Van Ingen Elarth in early childhood and two albums of unidentified people and scenes of the early 20th century (likely Elarth and her family). The final item in the series seems to have been artificially compiled after its acquisition, though a number of the photos show evidence of having been removed from an album.