The collection consists of the papers of the Oregon-based architect Thom Hacker, primarily original sketches and drawings for his projects. The majority of the projects represented in the collection were completed in Oregon. These include multiple structures at Oregon Health & Science University in Portland; libraries in Portland, Beaverton, and Bend; museums in Bend and The Dalles; the restoration of St. Mary's Cathedral in Portland; projects at Lewis & Clark College, the University of Oregon, and Southern Oregon University; and Hacker's own residence in Eugene. The collection also includes drawings for several projects that were never completed, including a lodge on Mt. Hood and residences in Eugene.

The collection also includes sketches and drawings for projects that Hacker did in Washington State and elsewhere in the U.S., including a residence for his in-laws, the Stewarts, in Yellow Springs, Ohio; the Fay and Bob Jones Studio in Skagit Valley, Washington; multiple buildings at Whitman College in Walla Walla, Washington; the Arizona Historical Society Museum in Tempe, Arizona; and the Yellowstone Art Museum in Billings, Montana. Hacker's student work at the University of Pennsylvania is also represented, including his thesis project. The collection includes a few materials relating to competitions for projects in Finland and in Mexico.

While many of the sketches and hand-done drawings in the collection are by Hacker himself, the collection includes work by employees of his firm, such as renderings by Richard Hoyen and drawings by Ken Kloj. Project records also include construction drawings; post-construction photographs, often as either prints or as film positives (most of which are in color); transparencies based on computer-generated drawings; and digitized or born-digital photographs and drawings.

Materials in the collection other than architectural project records include design records for a dervish vase and stemware that Hacker designed for Steuben Glass; a folio documenting the history of Hacker's partnership with Richard Garfield in the 1970s and 1980s; awards; and materials relating to an exhibition of Hacker's work at the University of Oregon Art Museum in 1978.