California Gold Rush relief map w
<a href="//commons.wikimedia.org/wiki/User:NorCalHistory" title="User:NorCalHistory">NorCalHistory</a>
2008-03-11
self-made; base of map is PD (<a rel="nofollow" class="external free" href="https://nationalmap.gov/">http://nationalmap.gov/</a> USGS US Federal Govt site)