Just for the record, not one tracker on this mission said they actually saw the "Spider-man" design in the prints they were following. In fact we were not able to get an identical shoe or a photo of the exact shoe he was wearing. There are many different styles of the Spider-man series and out of all of them that were located on the web, none ended up being the same shoe the subject was wearing. The trackers instead went on the size of the print, areas it was going and the characteristics of the sign to determine they were following the right Sign.
The photo is of one of the best prints that were found. You can make out some of the spider-man head and body but without a pattern to compare it to, it really didn't tell the trackers much.

Photo by Scott Evans
 Photo by Scott Evans and Rocky Mountain News |