As an architectural historian, architects’ drawings are often essential to my work. So I was dismayed when a recent article in the Detroit News reported that drawings and blueprints from Minoru Yamasaki’s (now defunct) architectural firm, including rare original blueprints of the World Trade Center Twin Towers, were being sold on eBay. The seller had salvaged them when the firm was throwing out its materials prior to a move (some of the firm’s materials were also rescued (literally at the last minute) when it went out of business and are now in Michigan’s State Archives). The preservation community is increasingly recognizing the value of Modern architecture and design and working to identify the most significant examples of the era...and I was proud to be part of the designations this year of Yamasaki’s McGregor Memorial Conference Center and Detroit’s Lafayette Park as National Historic Landmarks. Yet many Modern resources are under threat because their materials and systems are reaching the end of their useful life or the public has simply not yet recognized their aesthetic or historical value. I would include not only Modern buildings and landscapes in the threatened category, but also the sources used to research them. In the case of the Yamasaki drawings, it is fortunate that at least some of the documents were saved (although I would argue they belong in an archive where everyone can access them) when they were destined for the trash. But how many other architectural firms are throwing away potentially valuable documents because they lack the storage space, or the understanding to recognize their importance to future researchers? This era also utilized the first non-paper storage technologies – microfilm and microfiche, and even the tapes, floppy disks and early storage drives of the 1970s and 1980s. How many firms still have the technology to view these? And while Mylar was still used for some permanent drawings in this era, the majority of paper from the modern era will not survive for long, especially in the damp basements that are typically used for storage. Like the Modern resources they document, architects’ drawings, specifications, and planning documents from the mid-century era need to be valued for the information they can give us about the resources they represent and the era in which they were created.