Unless you’ll be camping in the Devil’s Postpile area, you’ll have to take a shuttle bus between 7:30 a.m. and 7 p.m. daily to get there. Instituted to alleviate traffic congestion in this very popular area, the bus cost $8 per adult or $4 per child ages 3-15, free for children under 2 years of age, round-trip service. Bus rides between stops in the canyon are free. If you’re going to camp in the Middle Fork Canyon of the San Joaquin River, you should know that the road from the Minaret Summit to Agnew Meadows is curvy, steep and scarcely more than one-lane wide. The shuttle is free after Labor Day into October.
The trailhead at Agnew Meadows are packed with the vehicles of hikers, and the meadow is even more packed with flowers. Horseback trips into the wilderness start at a pack station near here. Both hikers and riders visit such places as Shadow Lake, which the guidebook Mammoth Lakes Sierra called “one of the jewels of the Sierra, particularly because of its setting below the peaks of the Ritter Range.” It is a moderate 3-mile hike.
At Devil’s Postpile, you’ll see a jumble of talus of the Postpile (something like giant, polygonal Lincoln logs piled in the corner) made when basalt lava filled this place to a depth of 400 feet. As the basalt cooled, it cracked to form a honeycomb of columns – in fact, one of the best examples of columnar-jointed basalt in the world.
But volcanism was only one part of the story here best mountain bikes under 300 and in the Mammoth-Mono area. Glaciers were another. After hiking to the top of the Postpile, you’ll see the tiled floor finish of the column tops. A glacier 4,000 feet thick left not only polish, but also parallel scratches called striations. The glacier also plucked 100 feet worth of basalt off of this formation, although the columns are still another 280 to 300 feet and go straight down.
From the Postpile you can reach the end of Highway 203 at Reds Meadow. The meadow is a resort with a general store, cafe, cabins and pack station offering horse or wagon rides. Just before reaching the resort, you can camp at a Forest Service campground and luxuriate in it’s free hot-spring-heated bathhouse.