Photograph from 1892 of a pile of <a href="https://en.wikipedia.org/wiki/American_bison" class="extiw" title="w:American bison">American bison</a> skulls in Detroit (MI) waiting to be ground for fertilizer or charcoal.
<ul><li><a href="//commons.wikimedia.org/wiki/File:Bison_skull_pile.jpg" title="File:Bison skull pile.jpg">Bison_skull_pile.jpg</a>: Unknown</li>
<li>derivative work: <a href="//commons.wikimedia.org/wiki/User:Chick_Bowen" title="User:Chick Bowen">Chick Bowen</a> (<a href="//commons.wikimedia.org/wiki/User_talk:Chick_Bowen" title="User talk:Chick Bowen"><span class="signature-talk">talk</span></a>)</li></ul>
<ul><li><a href="//commons.wikimedia.org/wiki/File:Bison_skull_pile.jpg" title="File:Bison skull pile.jpg">Bison_skull_pile.jpg</a></li></ul>