It happens to me all the time. I read an article in the Des Moines Register. Some unspecified amount of time later, I think "Oh this would be perfect for that student!," or "Man, am I going to show Ben he's wrong" (love you dear). But can I find it? No, I can't. The Des Moines Register Website is hard for me to search, so what do I do?
There are two solutions. The first is that the State Library of Iowa provides access to a database of articles by the Register. The bummer of that is that you need your state library card to get access, and I need to get a replacement because I lost mine. If you have your card, it would be a great place because they offer full-text access.
The second solution is to try this link http://libhip.desmoineslibrary.com:8080/ipac20/ipac.jsp?session=132GQ96I17895.1740&profile=main&lang=eng&logout=true&startover=true#focus
or just go to the Des Moines Public Library catalog and click on the "new obit index" tab. They have a search engine where you can search for articles by various access points. It only gives me the citation for the articles that it pulls, but then I can look in back at my library for all issues from the past year.
Neither are perfect, but they have helped me out in a pinch--especially with those fun "hard copy" assignments!