The Mountains of California •
Thomas Mountain • Peninsular Ranges
• San Bernardino National Forest
• Riverside County

Start of the road off of State Route CA-74

Shot of the upper mountain about half-way up Thomas Mountain Road

Where I parked

This big boulder fell then split open

Old lookout tower footings

Looking over at the other potential highest point

Mount San Jacinto and Lake Hemet as seen from the farthest camping area

Date: May 11, 2013 • Elevation: 6,825 feet • Prominence: 1,945 feet • Distance: 3.5 miles • Time: 2.5 hours • Gain: 630 feet • Conditions: Sunny and dry


Thomas Mountain rises south of the San Jacinto Mountains in southern Riverside County. It's not considered to be part of the San Jacinto Range, although it connects to it at Keen Camp Pass near the town of Mountain Center. Instead, it is considered a part of the "Peninsular" Mountains, a broad grouping of peaks and hills about where Riverside, San Diego and Orange Counties come together, generally west of the deserts but not quite close to the ocean.

I was in the area, driving out this morning from Arizona and hiking nearby Cahuilla Mountain earlier today. From there, I drove back to state route CA-74 and went west a handful of miles, turning left onto Pyramid Peak Road, also marked by a Forest Service sign for Thomas Mountain. A road goes all the way to the top, and my intention was to follow this road most of the way up, then hike the rest. It was about 2 p.m. when I started the drive toward the top.

The road passes through a community of homes and small ranchettes, swings east, then becomes hard-pack dirt after the last of the homes. Although wide and solidly packed, the road was rather bumpy and rutted. I had assumed it would be in better shape for some reason. I slowed down to second gear and rumbled forward.

The road makes a bend west, narrows slightly, and contours in and out with the ridges and slopes of the mountain. Lower down, the flora was desert-like scrub and small trees. I kept with the road and plowed forward, covering about 6 miles in 20 minutes. I grew weary enough of the consistent ruts and grooves that I put the truck into 4-wheel drive for the last couple miles.

I rolled into the Tool Box Campground, elevation about 6,200 feet. I was high enough to be in mature pine forest, and the temperature was noticeably cooler, about 20 degrees less than down in the valleys below. I parked at the road junction marked "B" on the map. Looking at the map, the top was about a mile in a straight line from here. However, the road wiggled with the terrain, so I was looking at close to two miles each way and about 625 feet of elevation gain.

I locked up the truck and started my trek. I simply followed the road, a little beat from my earlier hike. I passed a big group of young adults who had taken over a camping area higher up, busy partying. They were nice and even offered me to join them for a beer. I appreciated their kindness, but they seemed like they had a good thing going, so I politely declined. I followed the road to the top, making a couple sharp bends as it surmounted the summit. Here, another couple in a SUV passed me.

The summit could be one of a couple of points. The first is marked by the footings of an old lookout tower. I walked to this point, tagged the highest rocks, took a photo, and eyeballed the other possible highpoint, a little farther west where the road ends. I walked over to there and met up with the couple from the SUV. They were parked and getting ready to pitch a camp here.

I ambled up to where they were parked and said hello. They had their four dogs with them. One barked at me but let me rub his ears, while another just barked furiously. The other two paid no attention to me. The couple was nice, and I explained my stupid hobby to them. I was looking for the benchmark but had no luck. While in "their" camp area, I stepped on any potential highpoint. I spent just a few minutes with them, and after tagging all potential highpoints, I started my walk out. Although the top is wooded, the views were quite spectacular in the open clearings. In particular, Mount San Jacinto stood tall immediately north, one of the best views I have ever seen of this grand mountain.

I followed the road back to my truck, taking a couple shortcuts down the open slopes. The party crew down below again waved hi to me, and I acknowledged them back. I was back to my truck after 90 minutes. I took a little longer than usual to change, relaxing in my camp chair in the shade of the big pines. I was in no hurry and I wanted to enjoy my time here.

Soon, I started the drive out, taking about 20 minutes to drive back to the main highway. From here, I drove through Mountain Center, then followed CA-243 to Idyllwild, where I parked and relaxed for about a half hour. I bought drinks, texted my family and my wife I was okay, and did my usual post-dirt-road engine and tire check. All looked good.

I drove north on CA-243 to where it drops into Banning. I topped the gas here, then got onto Interstate-10, heading toward my parents' place in Wrightwood. I was on the freeway for just a few miles when I heard a lot of clanging under my truck, then clunk-clunk-clunk. Something had obviously fallen off. Not knowing what was happening, I put on the hazards and parked on the dirt shoulder on the Interstate.

I could see something lying there on the freeway, sitting smack on the stripes separating lanes 1 and 2. I walked back to where I was abreast of it. It was a skid-plate from my undercarriage, just a hunk of metal that acts as a barrier to keep the sensitive parts of my engine from being hit by rocks and other road nasties. Obviously, it had worked itself loose after 215,000 miles, and the last rumble down Thomas Mountain was probably the last straw. Why it had to fall off on Interstate-10 and not a lightly-traveled mountain highway is a question for another day.

Well, I felt bad about leaving a large hunk of metal on the Interstate. Cars and trucks were avoiding it. I knew a new one would probably cost a small fortune. So I waited until there was a lull, and when there was, ran out to retrieve the hunk of metal. I was doing my civic duty to clear the road of a hazard, plus saving myself some money. I have to admit, feeling a little adrenaline rush running out into the busy interstate like I did. I think once is enough, though.

Back at my truck, I inspected the undercarriage to be sure it was all in good shape. It was, so I loaded the thing into the truck and started the remainder of my drive to Wrightwood, arriving there about 7:30 p.m. I spent the next couple days there, visiting family for Mothers Day and a pair of birthdays. Two days later, I would resume my hiking with a short climb of Mount Williamson in the San Gabriel Mountains.

Comment on the road up Thomas Mountain: Given the popularity of this area, this road sees a lot of vehicles and probably degrades faster than usual. I saw mostly stock trucks and SUVs, plus one small passenger vehicle. The road had one long section of very deep ruts, nearly a foot deep, where people had driven through fresh mud, then it dried. In other areas, erosion had created grooves and ruts, some sections including loose scree and crud. Clearly, 4-wheel drive is not mandatory in most conditions, but I would suggest a decent high-clearance vehicle as a minimum requirement, plus the usual patience. This became a "truck hike" of sorts.

(c) 2013, 2019 Scott Surgent. For entertainment purposes only. This report is not meant to replace maps, compass, gps and other common sense hiking/navigation items. Neither I nor the webhost can be held responsible for unfortunate situations that may arise based on these trip reports. Conditions (physical and legal) change over time! Some of these hikes are major mountaineering or backpacking endeavors that require skill, proper gear, proper fitness and general experience. .