<div class="description">
Exterior view of the portal of the 4 C Mine in Colorado.</div>
This file was contributed to Wikimedia Commons by <a href="https://www.wikidata.org/wiki/Q58036452" class="extiw" title="d:Q58036452"><span title="academic library system of the university of Colorado, Boulder">University of Colorado Boulder Libraries</span></a> as part of a cooperation project. The donation was facilitated by the <a href="https://en.wikipedia.org/wiki/Digital_Public_Library_of_America" class="extiw" title="w:Digital Public Library of America">Digital Public Library of America</a>, via its partner Plains to Peaks Collective.<span style="text-align:left">
<ul><li><a rel="nofollow" class="external text" href="https://cudl.colorado.edu/luna/servlet/detail/CUB~28~28~22~293834">Record in source catalog</a></li>
<li>DPLA identifier: <a rel="nofollow" class="external text" href="https://dp.la/item/1ef7a873e0b4c48ab96f9f350dd2a6f9">1ef7a873e0b4c48ab96f9f350dd2a6f9</a></li></ul></span>