Upper part of <a href="https://en.wikipedia.org/wiki/Muddy_River" class="extiw" title="w:Muddy River">Muddy River</a>, <a href="https://en.wikipedia.org/wiki/Moapa_Valley" class="extiw" title="w:Moapa Valley">Moapa Valley</a>, southern Nevada (note that the water is actually quite clear in this area)
<a href="//commons.wikimedia.org/wiki/User:Stan_Shebs" title="User:Stan Shebs">Stan Shebs</a>
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>