Devil's Postpile, Sierra County

A unique geological formation, Devil’s Postpile is a fascinating and picturesque site located on the Morristown Ridge about twenty miles northwest of Downieville. One can drive close to the site, and then the Devil's Postpile Trail is a 500 foot walk uphill to the base of the volcanic rock at an elevation of 5,720 feet.

Devil's Postpile was created by volcanic activities before the last Ice Age. Upon reaching the earth's surface with its cooling effect, the upward movement of lava began hardening and shaping into the basalt columns now known as Devil's Postpile.

Access: The total distance from the turn-off at CA State Highway 49 is 24.8 miles, with plenty of opportunities to get lost. Follow this description carefully:

From Camptonville, follow State Highway 49 east for 12 miles to the Cal Ida Road, which is on the left just past the Indian Valley Outpost. Or, from Downieville, drive west on State Highway 49 for 12 miles to the turn off located on the right. As you turn off, note the mileage on your car's odometer for future reference.

Proceed north on Cal Ida Road. The road is narrow and winding, so use caution. Logging traffic can be heavy so you might want to turn on your headlights. After 4.5 miles you will pass the old Cal Ida Mill. Directly after the mill the road forks. Follow the right fork for 11.2 miles. The road is paved and has become Forest Road No. 25. For the next several miles you will be driving through part of the 9,000 acres that burned during the 1987 Indian Fire. The Indian Fire was one of the 1,200 fires that blackened a total of 800,000 California acres during the "Siege of 87".

After traveling 11.2 miles from the old Cal Ida Mill on Road 25 you will pass the Eureka Diggins Area, a historic site from the Gold Rush era when Eureka City was a lively mining town. One mile past Eureka Diggins the pavement ends.

From the end of the pavement drive 2.5 miles to a point where the road forks. Take the left fork, staying on Road 25. After 1 mile, Road 25 veers to the left. Stay on Road 25. (Do not take Road No. 25-29). After 1.5 miles more the road forks again. Take the left fork, still Road 25. (Do not take Road No. 25-31).

Continue for 1.7 miles to the next fork. This time take the right fork. (Do not take Road No. 25-32, which leads to the Morristown Diggings.) Driving the last 0.7 mile, you will reach the trailhead where there is ample parking on the roadside.

Driving to the Devil's Postpile will take an hour, and it is miles away from the nearest phone. Let someone know where you are going and when you will be back!

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Latitude: 39.6707276 Longitude: -120.8827272 Elevation: 5947 ft
the best travel advice comes from the people who live here
Lee Adams

Recreational Opportunities

While only a 500 foot hike to the site, the hillside is steep and uneven. While the views from the top formation are stunning, be careful and watch for rattlesnakes. And remember you are miles away, and an hour from medical aid!

Seasons Accessible

Late spring to late fall. At an elevation of 5,800 feet, snow can make the site inaccessible for all of the winter season.


The site is on National Forest lands and there are no fees.

Pet Friendly Notes

Pets are welcome on national forest lands!


There is something wrong with the directions for getting to the Cal-Ida Road. According to my DeLorme Topo mapping system it is 11.88 miles from central Downieville, but only 8.6 miles from Camptonville., 8/1/2014

I finally located the Devil's Postpile on my DeLorme Topo mapping system. It is close to your distance at 24.5 miles from state route CA49, but DeLorme road designators differ considerably from yours. DeLorme shows GPS coordinates of Lat. 39.67074 North and Long. 120.88273 West with the postpile in Sierra County and not Yuba County., 8/1/2014

According to my DeLorme Topo mapping system it is only 13.4 miles from CA49 via County Road 509, Saddleback Road and Forest Road 21N16. CR509 begins about 0.4 mile south of Nevada Street in Downieville., 8/1/2014 There isn’t a Nevada St. in Downieville, and the directions do not state the postpile is in Yuba County. Cal-Ida Road is in Sierra County. Let us know when you and your DeLorme will be travelling - so we know when to call Search & Rescue!

Milly, 6/20/2016

There certainly is a Nevada Street in Downieville. Lived here for 67 years.

Keith Gregory, 7/16/2018

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