A wall of hexagonal basalt columns and a rainbow waterfall in the High Sierra.
Photo: Frank Kovalchek from Anchorage, Alaska, USA · CC BY 2.0 · via Wikimedia Commons
Tucked into the High Sierra near Mammoth Lakes, Devils Postpile protects one of the world's finest displays of columnar basalt — a sheer wall of tall, near-perfect hexagonal columns formed when a lava flow cooled and contracted roughly 100,000 years ago. Just downriver, the 101-foot Rainbow Falls throws a rainbow across its mist on a sunny afternoon. It's a small, magical place at about 7,600 feet — and snowbound most of the year, open only about mid-June through mid-October.
The columns are a short, flat walk from the ranger station, and a quick climb to the Top of the Columns reveals their polished, tile-like tops, scraped flat by Ice Age glaciers. The John Muir and Pacific Crest Trails run right through, and Reds Meadow valley makes a fine basecamp once you're in.
The catch is access. There is no entrance fee here, but there is almost no way to simply drive up. Reds Meadow Road is under snow into June — it opened on 13 June in 2026 — and once the Reds Meadow shuttle starts running (2 July to 20 September in 2026) it is mandatory from 7 a.m. to 7 p.m.: you park at Mammoth Mountain's Main Lodge and ride down for $15 an adult, $7 a child aged 3 to 15, free under 3. Outside those hours, and before and after the shuttle season, you can drive yourself in for a $10 Forest Service vehicle fee. The road is also being rebuilt over several seasons, so there are timed delays and escorted convoys on top of everything else. It's high country, so days are mild and nights cold, with afternoon thunderstorms common; pair it with Mammoth Lakes and the eastern Sierra.
Devils Postpile sits at the bottom of a narrow mountain road that is under snow most of the year and, through the busy season, closed to private cars altogether. Getting in means a shuttle from Mammoth Mountain — and getting to Mammoth means Tioga Pass from Yosemite when it is open, or the long way round on US-395 when it is not.
Ten miles west on SR-203 through Mammoth Lakes to Minaret Vista, then eight miles of steep paved mountain road down into Reds Meadow valley — about 30 to 40 minutes, with roughly three miles of it single lane. It is being reconstructed over several seasons, so expect timed delays and escorted convoys. In the busy season you ride it rather than drive it, which on a road this tight is a mercy.
The road that runs the length of the range past Mammoth. Everything on this side of the Sierra hangs off it, and it is one of the great American highways in its own right.
Over the crest from Yosemite Valley when it is open — roughly late spring to autumn. When it is shut, the drive between the two is many hours around the range instead of two over it.
Road open about mid-June to mid-October; shuttle mandatory 7 a.m.–7 p.m. while it runs
Check two separate things before you set off: whether the road is open, and whether private vehicles are allowed on the day you want to go. In the shuttle season the answer to the second is no between 7 a.m. and 7 p.m., and reconstruction adds timed delays on top of that.
TipThe shuttle also serves Rainbow Falls and the Reds Meadow trailheads, so it is more useful than it sounds, and one pass covers the whole day. Plan around the timetable — the last bus out of the valley leaves at 7 p.m.
A sheer wall of tall, strikingly symmetrical hexagonal basalt columns — up to 60 feet — from a ~100,000-year-old lava flow, among the finest columnar basalt on Earth.
Insider tipAn easy ~0.4-mile walk from the ranger station — flat and quick once you're off the shuttle.
Plan a trip to this spot →A short, steeper spur climbs to the top of the formation, where you look down on the polished, tile-like column tops — burnished flat by Ice Age glaciers.
Insider tipDon't skip the climb — the honeycomb view from above is the 'wow' most day-trippers miss. Watch your footing near the edge.
Plan a trip to this spot →A 101-foot waterfall on the Middle Fork San Joaquin, about 2.5 miles from the ranger station, where the mist throws a rainbow across the gorge.
Insider tipGo midday, when the sun is high enough to light the spray and produce the rainbow. The shuttle has its own Rainbow Falls trailhead stop, so you don't have to walk it from the ranger station.
Plan a trip to this spot →Naturally carbonated cold spring water bubbles up near the clear Middle Fork San Joaquin River.
Insider tipA quirky, kid-pleasing short detour off the main trails — don't drink untreated water; it's about the novelty.
Plan a trip to this spot →The famed JMT and PCT run right through the monument — one of the most celebrated stretches of both long trails.
Insider tipDay visitors can walk a piece of the JMT/PCT; Reds Meadow is also a classic thru-hiker resupply stop — fun people-watching.
Plan a trip to this spot →The broad volcanic valley holding the monument, the trailheads, and Reds Meadow Resort with its café, general store and showers — your basecamp once the shuttle drops you.
Insider tipOne shuttle pass covers every stop in the valley all day — get off at one trailhead, back on at another.
Plan a trip to this spot →High Sierra (~7,600 ft): short, cool, dry summers and long, deeply snowy winters. Even in July–August, highs reach only the upper 70s and nights drop to the mid-40s — though the monument warns a single day can swing from below freezing to near 90°F. Afternoon thunderstorms are common, so go early. The monument and Reds Meadow Road are open only about mid-June to mid-October, entirely snow-dependent — late snow delays opening and early storms can close it.
Via Mammoth Lakes — and for most of the season a mandatory shuttle replaces driving in.
Stage at the Mammoth Mountain Main Lodge gondola building. From Mammoth Lakes it is 10 miles west on SR-203 to Minaret Vista, then 8 miles of steep paved mountain road down — about 18 miles and 30 to 40 minutes, with roughly 3 miles of it single lane. While the shuttle runs, roughly July into late September, riding it is mandatory from 7 a.m. to 7 p.m.; outside those hours and outside that season you can drive in yourself. The monument charges no entrance fee — you pay either the shuttle fare or a Forest Service vehicle fee.
A small valley campground and resort cabins; hotels in Mammoth Lakes.
A small campground at Devils Postpile and Forest Service sites nearby, plus Reds Meadow Resort — cabins, motel rooms, hiker cabins, the Mule House Café, a general store and pay showers. Primitive, high and seasonal, open roughly July into mid-September.
Booking tipCampers with valley reservations and resort guests may drive the road, as may drivers with a disability placard. Everyone else rides the shuttle while it's running.
The full-service base — hotels, condos and dining, about 30 to 40 minutes above the valley. Ride the shuttle down each day.
Booking tipThe practical choice for most road-trippers.
Do I have to take a shuttle?
Yes, while the shuttle is running — in 2026 that is 2 July to 20 September. Between 7 a.m. and 7 p.m. you can't drive your own car in; you park at the Mammoth Mountain Main Lodge and ride the Reds Meadow shuttle ($15 adult, $7 child, or $30/$14 for three days out of five; under 2 free). You can drive in for a $10 Forest Service vehicle fee before 7 a.m. or after 7 p.m., before and after the shuttle season, or if you qualify — campers with valley reservations, Reds Meadow Resort guests, a disability placard or plate, rigs towing stock or watercraft, and licensed hunters. The dates shift every year, so check them.
When is it open?
About mid-June through mid-October, entirely snow-dependent — Reds Meadow Road has to be plowed open in early summer and can shut with the first fall storms. In 2026 it opened on 13 June. Confirm the current status with the monument before you drive up.
Is the road under construction?
Yes. Reds Meadow Road is being rebuilt over several seasons to widen it and improve safety, and the work brings timed delays and escorted convoys through the single-lane stretch. On delay days the shuttle runs a reduced timetable. Check the Inyo National Forest road page for the day's schedule before you leave Mammoth.
How long are the hikes?
The columns are an easy ~0.4-mile walk from the ranger station (with a short climb to the Top of the Columns); Rainbow Falls is about 2.5 miles each way from the ranger station, or a shorter walk if you ride the shuttle to the Rainbow Falls trailhead.
Should I worry about altitude?
Possibly — the monument sits around 7,600 feet and you stage even higher at Mammoth. Hydrate, pace yourself, and consider acclimating a day in Mammoth Lakes first.
When's the best time to go?
Mid-July through September for the most reliable access and mild days. Go early to beat crowds and afternoon storms, and visit Rainbow Falls around midday for the rainbow.
Can I combine it with Mammoth or Yosemite?
Yes — it pairs naturally with Mammoth Lakes and is a great add-on to Yosemite via Tioga Pass (itself a seasonal, snow-gated road), plus Mono Lake and the US-395 corridor.
Pick your vehicle, line up the stops on the way in and out, and carry the whole route in your pocket.
