This series consists of incoming and outgoing correspondence from Williams' office. It includes correspondence with constituents, other congressmen, and others. A great deal of the series consists of the issue-oriented form letters that were sent as responses to constituent inquiries.

This series consists of the materials that Williams' office collected and generated in the course of legislative activities. The files include publications, notes, memorandums, issue-related correspondence, voting records, and the bills that Williams introduced.

This series includes the texts of speeches presented before bodies such as the Montana Senate and House, the National Congress of American Indians, the American Bar Association, the National Community Action Foundation, and his responses to selected weekly Presidential radio addresses. The Congressional Record section includes photocopies of Williams' statements from that publication; these were gathered, copied, and listed by Williams' staff, and there is an index by topic and date at the beginning of each folder. There are a few Special Order Statements.

This series consists of press releases issued in the U.S. and Montana by Williams' office. The releases offer a digest of Williams' legislative actions, reactions to events, and excerpts from his congressional testimony and addresses. Most are photocopies from originals.

This series is composed of Congressman Williams' travel schedules and contains hourly, daily, and weekly schedules, correspondence, and maps. There are separate sections for general travel and for travel in the District of Columbia.

This series consists of newspaper clippings from Montana newspapers. Materials were collected on political issues from December 1978 to November 1996 by Williams' staff. Most of the articles are directly concerned with Montana, including the long-debated Wilderness Bill. Other issues include the Alaska Land Bill, the Chicago and Milwaukee Railroad, Amtrak, the Libby Dam project, ARCO, the Federal Aviation Administration, and other concerns of Montanans.

This series consists of materials associated with Williams' accomplishments in office and with his retirement. Materials labeled accomplishments were gathered by his staff and consist of articles, press releases, correspondence, and office memoranda. Retirement materials consist mostly of notes of thanks to and from constituents.

This series contains legislative materials, correspondence, maps, reports and printed material. They represent the attempts by Pat Williams and Staff Member Art Noonan to define areas within the borders of Montana that should receive wilderness protection. Many materials deal directly with the needs of Montana communities and industries throughout the wilderness designation process.

Included is information from early wilderness debates through the development of the RARE II process and specific wilderness boundaries. Much of the material deals with specific Senate bills and House resolutions, such as S. 1696, S. 2790, S. 489, H.R. 6001, H.R. 2090, H.R. 2473. Additionally, this series contains materials on related issues such as geothermal protection (in H.R. 3359 and H.R. 723, the Old Faithful Protection Act), a proposed repeal of the 1872 mining law (H.R. 918), the Northern Rockies Ecosystems Protection Act, the Nez Perce National Historical Park (H.R. 2032 and S. 550), as well as some materials addressing general land and resource management of public lands. These general public lands materials are housed within the Wilderness Series both as a reflection of the context within which they were received and the subtle distinction between formal wilderness designation and broad wilderness concepts among many private citizens and journalists.

This series contains Williams' public collection of video tape materials collected while in Congress. VHS, Beta, two-inch, and 3/4 inch formats are inter-filed. This series contains recordings of selected floor speeches, floor debates, public service announcements, messages to constituents transmitted to Montana broadcast stations, nationally broadcast news segments, panel discussions, speeches to professional organizations, and materials produced by Montana organizations and individuals related to Pat Williams' congressional activities. This collection also contains two phone conversations with radio stations recorded on audiocassette tapes.

This series consists of the guest books kept in Williams' D.C. office and of portraits produced by students of Williams. Most of the portraits are from Montana schools; the artists range in age from kindergarten to high school.

This series contains portraits taken during Williams' time in Congress. Images are mostly of Williams and/or close associates at a variety of events. Photographs of events he attended, including Democratic National Conventions, are also included. Images are of both Montana and Washington, DC.