Is the Buffalo on the National Park Service emblem/logo something recent?

I don’t recall seeing the Buffalo on the National Park Service emblem/logo until recently. Was it always there and never shaded in with white or is it entirely new alltogether? I dunno,
I’m verklempt.

It looks like it was always there. This is the explanation that the NPS gives about the logo:

http://www.nps.gov/faqs.htm