Our time at Mono Lake was so beautiful, between the ideal boondocking spot overlooking Mono Lake and 70’s/40’s temperatures, it was very hard to leave.
But, with so many other things to see and somewhat of a schedule to keep, we continued our journey south to the Devil’s Postpile National Monument.
The short history of these unique formations is that approximately 100,000 years ago a 
lava flow erupted two miles upstream. As it flowed down the valley it eventually ran into an obstruction which served as a dam causing the lava to pool up to as deep as 400 feet. Conditions were such that the lava cooled at a very slow rate, and as it cooled it contracted and cracked forming hexagonal columns. The hexagon, one of the nature’s most stable and sturdy shapes, also found in turtle shells and honeycombs.
It’s hard to grasp the enormity of these posts until you’re standing at their base. They average 2 feet in diameter and many are up to 60 feet long. Together they look like tall posts stacked in a pile, hence the name.
The short but steep hike to the top of the Postpile was a reminder we’ve been out of this elevation for awhile – and definitely worth it. A glacier removed much of the rock on top of the Postpile, and left scratched and polished tiles locked together like nature’s dance floor.
As incredible as this site is, it’s even more incredible to consider it was almost blasted to bits. Devils Postpile was once part of Yosemite National Park, but discovery of gold in 1905 near Mammoth Lakes prompted a boundary change that left the Postpile on public land. A proposal to build a hydroelectric dam called for blasting the Postpile into the 
river, but luckily concerned Californians made sure the area was protected as a National Monument.
On our way out of the area we stopped at the Earthquake Fault, a crack in the rock about 20 feet wide and 60 feet deep. It is said that snow from winter often lasts year round (making it a great place to store food pre-Frigidaire).
We only scratched the surface and with so many other interesting things to see and do, we may have to revisit this area and plan more time.
I love this place and am so glad you posted about it! I spent a summer working in Yosemite so I’m very familiar with Mono Lake and so many other areas around there. The Devil’s Postpile and the entire Mammoth Lakes area is such a hidden gem (compared with the throngs in Yosemite).