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Special Collections and Archives

Tips and tools for researching primary sources in Special Collections and Archives and online

Search Cal Poly's digitized primary source collections

Explore over 60,000 items digitized from the Special Collections and Archives collections. 

The Online Collections is a growing database with materials added every day, featuring photographs, letters, videos, audio, architectural drawings, and more.

Is this collection digitized?

Many of our collections have digitized content. Here is an easy way to see what has been digitized and is available online: 

Advanced Searching

This is how you can see if a specific folder is digitized in a collection.

You can check to see if a specific folder or item has been digitized by searching the image identifier number (a unique number for each item digitized). To determine the part of the identifier you will search by, visit the inventory of the collection you’re interested in on OAC. When you find the folder you want, note down the 5 areas of the finding aid in the below screenshot, and combine them in order and separated by a dash. For the screenshot example, the string of numbers and letters you would arrive at would be: 002-1-d-01-06


Next, go to:, and change the Field to “Identifier”. Then insert the string from the last step into the Search terms box, adding a wildcard (asterisk) at the end, as seen in the below screenshot.


Click “Search” and the items that have been digitized from that folder should appear. Note that there are many folders from which no items have been digitized, so a search with no results should not be unexpected.