Saturday, June 28, 2014

Clamshell Peak

Hiked: 6/27/2014
Distance: 8.3 miles round trip on dirt road and use trail
Summit Elevation: 4360'
Elevation Gain: 3435'
Elevation Gain (in Empire State Buildings): 2.74
Round trip time: 5 hours 15 minutes
Recommended water: 154 oz.*
Parking/Fees: Free on Ridgeside Drive
Difficulty: Strenuous

* I took 128 oz and ran out, recommend 154 oz in the summer

Another Sierra Club Great Lower Peak in the ANF between Mt. Zion and Mt. Bliss. I did the alternate route starting on Clamshell Truck Trail, then up the firebreak. I very much underestimated the effort and water required for this hike. I parked a little ways away from the driveway that leads to Clamshell Truck Trail. The road starts out with a gentle gain and winds around Ruby Canyon about a mile until you reach an obvious firebreak going up on the right. There was a Monrovia ranger truck parked there with the windows down, but no ranger in sight. I started up the firebreak wondering if I would run into him doing some kind of maintenance or rescue, but I never saw anyone and the truck was gone when I got back. The firebreak separates Ruby Canyon from Clamshell Canyon, and is easy to climb at first. A very steep section starts at the 2 mile mark and gains 1500' in the next mile. Worse, it is over loose dirt. A few times, I grabbed small brush or large clumps of grass to aid my ascent.

Clamshell Truck Trail

Monrovia park ranger truck in front of the firebreak to Clamshell Peak

Some kind of structure ruins, or a camp site

Up and OMG UP

After topping the initial ridge, the trail deteriorates into criss-crossing animal trails. I also found a pink metal marker after the first steep section but no benchmark or sign. Going up, it was pretty easy to stay oriented, but not so coming down. The last mile to the summit only gains about 950', but sections of animal trail are completely overgrown and must be bashed through. The vegetation is mostly knee high to waist high grass, weeds, and other soft plants. At the very end, the trail opens back up onto the overgrown Upper Clamshell Road, a welcome change. No poison oak on the ridge line, but there is a little poodle dog bush. There is almost no shade the entire way except a few smallish trees that provided a few square yards of relief. You climb over numerous bumps and a false summit, never seeing Clamshell Peak until near the very end. The summit itself is flat with good views of Rankin/Monrovia Peaks, Bliss, and Mt. Wilson. I found the summit register in a buried concrete bunker under a large iron grate. Spiders had built webs over the register cans. I cleaned up the cans and unwrapped the registers from 6 plastic bags. There were two small notebooks, one going back to 1987. Before me, Clamshell was last visited in April. It is not visited very often. I signed the register and returned it to the concrete bunker. I forced myself to eat something, but the heat had killed my appetite.

Pink metal marker after the first steep section, no benchmark, no signs

False summits in the distance

Following animal trails

First look at Clamshell Peak from the false summit

Clamshell guarded by yucca

Concrete bunker with register

Register and 6 protective plastic bags

First entry, Jan 24, 1987

April 24, 2014 was the previous entry

Mt. Wilson from Clamshell Peak summit

Rankin and Monrovia Peaks from Clamshell

Soon, I started down, following the same animal and bushwhacked trails. I blindly followed the best animal trail right down the wrong ridge. When the area started looking unfamiliar, I checked the GPS and saw my mistake. I had to climb 100' back up to find the path down the right ridge and that is when I ran out of water. I took 128 oz, but needed about 154 oz, and put that number in my summary. Back on track, I could not descend too quickly due to the angles and loose dirt. While difficult, it was still much easier than going up. Without water, I was dehydrated by the time I reached the road, and even more so when I got back to the car. Fortunately, I had plenty of water in the car and did nothing but drink until my thirst abated. My stats reflect my mistakes. With no errors, the round trip is 8 miles and 3335' of gain, with most of the gain concentrated in the last two miles. Light bushwhacking both ways and some route finding needed on the way down. I can see why some people continue over Rankin and Monrovia because most of the gain is done by the time you get to Clamshell and you don't have to come down the steep dirt. Clamshell is a tough little peak on this route. It was my 100th listed Sierra Club peak.


  1. I did this over the weekend with two friends. We kept going over Rankin and Monrovia peaks and then down to White Saddle, down past Trask Boyscout camp and then down out of the Monrovia canyon park and then back up Ridgeside Dr. to the car. That turned out to be about 18 miles total,and we were TIRED. It took about 11 hours total-- we were very worried about going back down that steep section you mentioned. I wish I had read this before we went. The pink metal marker is not there anymore, but someone has helpfully put up pink ribbon on tree and bush branches to help guide the way to clamshell peak. The pink markers kind of disappear after that first peak. Someone else has slipped a GIANT plastic cockroach into the trail marker ziplock, so be prepared! Once up there already Rankin and Monrovia were not too bad although there is some steepness there too, but nothing like that first climb. Thank goodness it was early enough in the year that the vegetation was green enough to use for handholds. The day was not too hot and I had 100oz of water and did not even use it all on this trip. But I wouldn't want to do it in the hottest part of the year for sure.

    1. Lesliepop,

      Thanks for the trail status update and cockroach warning. Clamshell is not heavily trafficked and not easy to find. Heading over Rankin and Monrovia after Clamshell is a very big hike, but I get why people do it. You have already done the hard part.

  2. I did this yesterday. the trail to the pink metal marker is gnarly to say the least. Overgrown, slippery and steep. But from the marker all the way to clamshell and even to rankin and monrovia, it's all bull dozed fire break, which can be very steep (how did they get a bulldozer to do this?). It's also easy to follow, but kind of rough to walk on, but it's better than fighting the bushes. It took me 5 hours to get to Monrovia peak. No one else out there. views are great. some nice forested area between clamshell and monrovia. Drank 4.5 liters of water. I can't remember the last time I had to stop and catch my breath so many times. Incredible rugged journey. Also, you have to park 1/2 mile from the clamshell truck trail, because the neighborhood has restricted parking now. GPS at parking area said 775 feet, so counting the ups and downs it's over 5000 ft elevation gain.

    1. Unknown,

      No doubt about the steepness of the ridge before the marker. I've seen pictures of the new firebreak, a good idea given how much fuel was up there. I think you picked a good time of year to go. It was hellish up there in the summer. Nice work getting Monrovia and Rankin. I still haven't made it out to those two.