I found some great pictures of Idaho Falls on the USGS' website. They didn't know when the pictures were taken, but based on the content it's been a while. I'm sure an avid historian could probably place the photos based on the content but I am not such a person. I can still appreciate them.
So without further ado, here are the pictures. I believe them to be in the public domain. They are about 2.5MB each.