TRAIL Content

The TRAIL Collections Working Group chooses and prioritizes what series will be added to TRAIL. Any library or other organization may contribute needed content for any active series.

See the Series List to learn which series have been digitized or the status of a series under review for digitization. 


HathiTrust storage architecture has two synchronized instances of storage with wide geographic separation and an encrypted tape backup with 6 months of previous-version retention.  For more information, see
The University of North Texas maintains redundancy for all the content in the UNT Digital Library system.  For every file there are at least two copies (both preservation files as well as all of the access files that are getting viewed online).

There are several reasons. First, if our series processing inventories indicate that we still need the report, we actively seek the report.  We do not have the staff to check our needed items against what was digitized and made available in HathiTrust by another content provider.  Second, ONLY reports digitized by TRAIL are indexed and searchable by our search interface.  Finally, technical reports that have maps, foldouts, etc. are rarely included in the reports available at HathiTrust.  TRAIL sends these reports to the University of North Texas (UNT), our other TRAIL repository, where the maps, foldouts, etc., are digitized along with the reports.

It’s quite likely that we do.  You may have reports that will fill in the gaps for series we’re working on.  Please compare what you have against the TRAIL Series Inventories.
If you cannot find the series that pertain to your reports, please contact the TRAIL Collections Working Group Coordinator (the Coordinator’s name and email can be found here).   This person leads the group that determines which series TRAIL will consider for digitization.

No, not at present.  The TRAIL Search Interface does not have a "browse" function because a large share of TRAIL content consists of documents for which agency names and series titles have changed frequently over the years.  Creating and maintaining an authority record structure, which would pull together all the variant combinations for each agency/series pairing, would require a significant investment of our resources at this time.

See the list of contributing Institutions on the website of TRAIL Collections Processing Database.

Some digitized reports may not be available due to copyright restrictions. TRAIL content in the HathiTrust is subject to copyright decisions made by HathiTrust. For more information about copyright see the HathiTrust copyright page.

Anyone can download TRAIL documents, page by page. HathiTrust partner institutions can download documents page by page or can download a PDF of the complete document.  The complete document is available for viewing online. For more information see the Access Chart on the HathiTrust Help page.

Individual print documents that are easily scanned (destructive process) are preferred. TRAIL is currently digitizing a set of microcards. TRAIL is also developing guidelines, processes, etc. for digitizing maps. Special formats including maps and other non-standard sized items are deposited at the University of North Texas Digital Library

It is a freely searchable database that provides the details about the series that have been received, inventoried, and processed at the University of Arizona, the central processing site for TRAIL.

TRAIL content is open for indexing by any/all Internet search engines.

Any interested library may purchase sets of provider-neutral catalog records for available collections via OCLC. These OCLC Record Sets enhance access to existing print collections or electronic versions.

Digitized technical reports are located in HathiTrust and in the University of North Texas Digital Library.

General Information

See About TRAIL on the website of the Center for Research Libraries in the Global Resources section.

Use the TRAIL Search Interface, which is maintained by the University of Washington Libraries.

TRAIL began as a Greater Western Library Alliance (GWLA) project with the Center for Research Libraries to increase access to and preserve government technical reports. TRAIL is now a CRL Global Resources Network Initiative which provides unrestricted access to this unique body of literature via the TRAIL Search Interface.

  • communicates research in technology and science (prior art)
  • contributes to the continued growth of research at institutions and in industry
  • serves specialized audiences of researchers (e.g. aerospace, mining, energy, etc.)

Government documents that have not been digitized or that are not born-digital are vulnerable for a number of reasons:

  • libraries are downsizing print government documents collections due to space issues
  • many government documents are deteriorating or are being moved to remote storage
  • for many of these documents, access exists only through series records in library catalogs, if at all, while TRAIL individually catalogs each document.
  • acquiring content from donor libraries
  • arranging for digitization of the materials, including large fold-outs and other special-handling materials
  • cataloging/creating metadata for each report
  • arranging for storage/preservation of digital files
  • creating and maintaining the user interface that provides access to TRAIL digitized content

To ensure preservation, discoverability, and persistent open access to government technical publications regardless of form or format.

TRAIL Membership

No. Any of the following will benefit TRAIL:  membership dollars, service on TRAIL working groups, educating others about TRAIL, donation of materials.

Through regularly scheduled phone conferences and through a workspace site (wiki) provided by CRL.  Members use the CRL wiki to create, post, and edit the documentation of the TRAIL Steering Committee and Working Groups.         

  • TRAIL Collections Working Group
  • TRAIL Communications Working Group
  • TRAIL Processing Working Group
  • TRAIL Membership Working Group (new!)

Dozens of academic, government, and commercial organizations have contributed content, services, funding, and staff time to TRAIL and members invest in these efforts to keep it going and growing.

Search U.S. government technical reports issued primarily prior to 1976 and digitized by TRAIL.