Camping Map Avatar

I've noticed recently that some members have an avatar in their posts that shows an outline map of the US with the states visited colored in. I think this looks great and would like to add the same to my posts but have been unable to locate the outline map despite my searches here and on the web at large. I know how to add an avatar by going to the CP section and adding a custom avatar but I just can’t locate an outline map file.

As always, your help is appreciated.