“Mammoth” conjures in my mind images of rich kids whose families went skiing during Christmas vacation, and I’m sure it’s a glorious place in winter for wealthy skiers, with 400 inches of average annual snowfall, 28 lifts, and lots of swanky shopping, condos, and restaurants. But there’s a lot to see and do in summer as well.

Like so many beautiful places in California, the Reds Meadow Valley on the back side of Mammoth Mountain (adjacent to the Ansel Adams Wilderness and the Pacific Crest Trail) had been loved to death by summer tourists, so now no cars are allowed and a shuttle bus takes visitors down into valley to begin backpacking trips and to see several interesting sights, including the “Devil’s Postpile.” We took the shuttle bus down and walked the short hike to the foot of the Postpile. Amazing!

About 82,000 years ago, basalt lava flowed here from an unknown source. Columnar jointing occurs when certain types of lava contract while cooling. Because the flow was very thick in this location, much of the mass of pooled lava cooled slowly and evenly, which is why the columns are so long and so symmetrical. Then around 20,000-12,000 years ago, a glacier pushed down the middle fork of the nearby San Joaquin River and carved away one side of the Postpile, exposing a sheer wall of columns 60 feet high. Erosion and earthquakes later knocked down some of the columns, which now lie in a broken heap at the foot of the Postpile.

If the lava had cooled perfectly evenly, all of the columns would have been exactly hexagonal, but some of the columns have 7, 5, or 4 sides due to variations in cooling. We didn’t hike to the top, but I found a picture that shows what the columns look like at their top end:

After we came back up out of the valley, we took a gondola to the top of Mammoth Mountain.

At the summit we were at 11,053 feet!

I could definitely feel the altitude, like a hand pressing against my chest. I’ve never been that high before.

The views out over the Sierras were just stunning.

Many of our fellow travelers brought mountain bikes up with them on the gondola, to ride more than 3,000 feet down the mountain over the 100 miles of mountain bike trails that zigzag across the ski slopes. It looked very fun! for someone else. Not me.