Distance: 11.8 miles round trip on trail and cross country
Summit Elevation: 3675' (El Cajon), 2388' (Silverdome)
Prominence: 1955' (El Cajon), 488' (Silverdome)
Elevation Gain: 4073' (combined, 588' for Silverdome)
Elevation Gain (in Empire State Buildings): 3.25
Round trip time: 5 hours 40 minutes
Recommended water: 104 oz.
Parking/Fees: Free in parking lot or on the side of Wildcat Canyon Road
El Cajon Mountain is sometimes called the most difficult hike in San Diego County. I don't think that's true, since some of the desert peaks are beasts. Regardless, El Cajon is formidable with roller coaster hills and significant gain on the return with no water anywhere. I planned to do this in late August, but a ranger stopped me at the trailhead. Turns out the entire trail is closed during the month of August due to the heat, or so I was told. This was my second attempt. My main goal was El Cajon, but I was also interested in exploring Silverdome, a mysterious, granitic dome, rumored to be the largest granite monolith in San Diego County. I could find very little useful beta on Silverdome and no trip reports. Silverdome, just off the trail, would be a bonus if I had the time and energy left on return. In addition to the regular trail to El Cajon, there is a class 3 route and several class 5 routes.
San Diego County operates the El Capitan Open Space Preserve, and they want you start this hike early. The parking lot opens at 7 AM and closes at 4:30 PM. They want you out by 4:30 PM and have signs on the trail reminding you of that. In fact, based on the signs, it seems they would rather you not be on the trail at all. The hike starts with a moderate gain up a road until the trail starts. This hike has a unique elevation profile. It has almost no level areas. You are always going up or down. Back to the crazy signs. Every mile or so, there is an elevation profile with a "you are here" marker so you can see your progress. However, I got the impression the signs were really saying, "You can't do this, loser, go back home and eat twinkies on your couch". That was reinforced with a special stop sign and warning that if the time was already 12:30 PM, you should stop and go back. I've never seen signs like this on any trail. Maybe they've had to do a lot of rescues. Who knows? It was bizarre.
Shortly before the summit trail junction, there is a burned out vehicle on the side of the trail. As you approach the El Cajon summit, the trail comes to a 4-way junction. To the right is a short climb to peaklet 3370', straight ahead goes to the south cliffs overlooking El Capitan Reservoir, and left is the use trail to the summit. There are well marked signs for the summit trail. The final ascent requires some light scrambling and the official benchmark is on an easy to climb 10' boulder. I ate some snacks on the summit boulder and rested a bit. I found a summit register between two rocks near the summit boulder. It was filled with small slips of paper, one of which I signed, some trail snacks, and a thoughtful tube of sunscreen. Other hikers made it to top while I was on the boulder, but they chose not come up. Perhaps it was my gentle aroma of Saturday night party, sweat, sunscreen, and bug spray that kept them away. I took the requisite photos and started down.
On the way up and back, I searched for a way up Silverdome as I passed it. FYI, Google Earth has the wrong peak marked as Silverdome, confirmed by Peakbagger, Trimble, Topozone.com and my GPS. Google Earth also has Potato Mountain wrong in the San Gabriels, but I'm not sure who to inform. Silverdome is just about 3/10s of a mile off trail, but has no use trail that I could find. Just before the 2 mile marker, I took a few minutes to estimate my chances, then forged ahead at the least dense section of brush. The moss and lichens covering sections of granite were very soft and I sank in a couple of inches whenever I stepped on it. I quickly got to the first clear slab of granite and climbed 100' vertical or so before hitting more brush. It was a class 2/3 bushwhack from there, but all class 3 sections could be easily bypassed. In 30 minutes, I was on top where I found a cairn, but no benchmark or register. There were some interesting boulders on top and steeper drops on the other side. I made no attempt to follow the same route down that I used coming up. I followed animal trails where possible, then rocks or slabs if possible, otherwise bushwhack city. I hit the trail in a different spot from where I started for about a one hour side trip.
El Cajon South Arete