This was shot at the 20 Mule Team Canyon in Death Valley Canyon, California (2.5 mile long canyon). 20 Mule team was a team of 18 mules and 2 horses that used to transport Borax in wagons from the mines in Death Valley.
Interesting fact: Parts of Star Wars - Episode IV -- A New Hope and Star Wars Episode VI -- Return of the Jedi was shot in this canyon. Source: <a href="https://www.nps.gov/deva/planyourvisit/star-wars-in-death-valley.htm" rel="noreferrer nofollow">www.nps.gov/deva/planyourvisit/star-wars-in-death-valley.htm</a>