Rainbow Falls (Sierra Nevada)

Rainbow Falls

2.5 miles round trip, 400 feet elevation gain
Difficulty: Easy
Access: Devils Postpile bus to trailhead (unless arriving before 7 AM), Devils Postpile National Monument entrance fee and bus fare required

At Rainbow Falls, the Middle Fork San Joaquin River makes a spectacular hundred-foot plunge down the columnar basalt characteristic of California’s Devils Postpile National Monument. One of the most significant waterfalls in the Sierra Nevada outside of Yosemite Valley, Rainbow Falls is a highlight of Devils Postpile National Monument and a must-visit for summer visitors to the Mammoth Lakes region. The hike from Reds Meadow Road down to the falls is quite easy, if fairly nondescript until the end; however, reaching the trailhead is a bit more complicated as Reds Meadow Road is restricted to bus traffic alone in the day during the summer and is closed the rest of the year. While hikers wishing to drive to the trailhead can do so if they arrive at Minaret Summit before 7 AM, most visitors will need to take a bus to reach the trailhead from Mammoth Mountain.

I hiked to Rainbow Falls on an early July morning: as the bus system was in effect, I found myself arriving at Minaret Summit at sunrise to be able to drive to the national monument. From the center of town in Mammoth Lakes, I followed Minaret Summit Road to the northwest, crossing the saddle and passing the entrance kiosk to enter the San Joaquin watershed. The entrance kiosk was not staffed at 6 AM but it is staffed later in the day- expect to stop at the kiosk on your way out to pay entrance fees. At this point, the Minaret Summit Road became the Reds Meadow Road and began descending into the Middle Fork San Joaquin River valley. While the road was paved the entire way, the stretch of road just past Minaret Summit was hairiest: here, there were no lane divides, with two-way traffic on a windy mountain road (including occasional buses) accommodated on a single lane road. After reaching the bottom of the valley and passing the Agnew Meadows turnoff, the road became an easier drive, with defined lanes the rest of the way down to the right turnoff for Rainbow Falls. I made a stop at Devils Postpile first, so I did not arrive at the Rainbow Falls Trailhead until about 8 AM, when I snagged the very last spot in the small parking lot.

From the parking lot, I followed the trail through the forest gently downhill towards Rainbow Falls, crossing the combined John Muir and Pacific Crest Trails about 200 meters after leaving the parking lot. At 0.4 miles from the trailhead, I passed a junction with a trail that headed back uphill towards Reds Meadow Lodge. The forest began to thin out after this point, opening up views of the Ritter Range rising to the west.

At two-thirds of a mile from the trailhead, I came to a junction where the right fork led to Devils Postpile and the left fork to Rainbow Falls. I took the left fork. At this point, the descent from Reds Meadow Road ended and the trail followed a flat plateau above the Middle Fork San Joaquin River. The dwarf forest here is a result of the slow recovery from the 1992 Rainbow Fire than burned through this area; in 2020, this area was just a mile away from being burned by the Creek Fire, one of the most severe fires in California history. 

Ritter Range

The thinned-out forest provided nice views of the Ritter Range to the west and Mammoth Mountain to the north. I could see the gondola station atop Mammoth Mountain from here: Mammoth's north slopes are home to one of California's premier downhill skiing areas. Mammoth Mountain is a lava dome volcano, created by the same geological forces that are responsible for Long Valley Caldera to the east and the eruptions that created the columnar basalt found at Devils Postpile and Rainbow Falls.

Mammoth Mountain

At just under one mile from the trailhead, I came to a junction with the Fish Creek Trail. Here, I took the right fork, which continued to follow the Middle Fork San Joaquin River and began descending again. The trail here approached the river close enough to provide the first views of the Middle Fork San Joaquin River just above the lip of Rainbow Falls. From here, there were nice views up the length of the river towards the Sierra crest and Two Teats.

Middle Fork San Joaquin River above Rainbow Falls

Continuing to descend, at 1.1 miles from the trailhead I  came to my first view of Rainbow Falls. The first overlook gave a lovely view over Rainbow Falls, where the Middle Fork San Joaquin River plunged a hundred feet into a pool at the base of a columnar basalt gorge. The vertical striations of the rock walls of the gorge were a pleasing aesthetic complement to the vertical drop of the falls. The columnar basalt at Rainbow Falls and at Devils Postpile was formed when cooling lava cracks and contracts, forming vertical hexagonal columns. The view here was lovely, but this wasn't the end of the hike, so I continued to follow the trail downhill.

Rainbow Falls

Shortly after the first overlook, I came to the second overlook, where I had a slightly different angle on the waterfall; here, I was below the lip of the waterfall and could better appreciate the curtain of water formed by the falls.

Rainbow Falls from the middle overlook

Past the second overlook, I came to the top of a steep descending trail that dropped down into the gorge to visit the base of Rainbow Falls. The staircase descent was quite steep here and required negotiating some large steps, but it was thankfully short and brought me to the end of the hike at the pool at the base of Rainbow Falls. This was the ultimate viewpoint for the falls, where I could appreciate this wall of water constantly plunging over the basalt cliffs. The falls' fine mist engulfed me in a refreshing shower, even though I was still over a hundred feet from the base of the falls itself.

Base of Rainbow Falls

The return was straightforward: I retraced my steps back to the car. The return journey is uphill, so most of the physical exertion on this hike happens after you've enjoyed the hike's main attraction. On the drive back out to Mammoth Lakes, I stopped at the Minaret Summit entrance station to show my America the Beautiful Pass- visitors who come without a pass will still need to pay their entrance fee here.

Rainbow Falls is one of the loveliest waterfalls in California outside of Yosemite and a top attraction in the Mammoth Lakes area; visitors should couple a stop at Devils Postpile with this short hike to see Rainbow Falls. The area is only accessible in summer and visitors must take the Reds Meadow bus unless they arrive early enough to drive the road to the trailhead.