In my quest of replacing previous drive-ups with hikes, Homer Meek and I bagged Thomas Mountain on October 21 via the Ramona Trail and assorted dirt roads. The starting point was just off SR 74 at the intersection with Forest Road 6S04. This is about 4.2 miles north of the intersection of SR74 with SR371 coming up from Aguanga. Immediately after turning onto 6S04 there is a large parking area. We followed the road to the west about 1/4 mile to the start of the Ramona Trail on the left, the sign says "Tool Box Spring 3-1/2." We were not sure of the remaining distance to the peak since it was hard to gauge from the Forest Service map and a very old 15-minute Idyllwild topo. However,
Luella Fickle's trip writeup in the Jan-Feb 1991 Lookout described a hike on 9/22/90 which started from SR74 and reached the top via Tool Box Springs Campground in time for lunch.
We started at about 9:15 am and the weather was perfect. The Ramona trail is in excellent condition and rises slowly with many, many switchbacks. Along the way there are outstanding views of Garner Valley and San Jacinto and the Desert Divide peaks to the east. Shortly before the estimated arrival at Tool Box Springs, we encountered a good trail veering sharply off to the right. Since this seemed in the logical direction to the Thomas Mountain ridge road (5S15), we took it. After a few minutes we arrived at a picnic area with a dirt road leading away (west) from it. This was not the Tool Box Springs campground but served as a shortcut to 5S15 anyway. After another few minutes we reached 5S15 and turned right. Eventually the road has a major switchback to the left and then to the right and we soon arrived at the Ramona Campground. Shortly after that is the Thomas Mountain Campground, marked by a prominent dual outhouse just off the main road. Across from the campground we took a dirt road rising to the west. This road took us to the summit in about 0.5 mile. Our hiking time was about three hours and it was time for lunch.
There are several foundations for former lookouts or other facilities in the summit area. The views to the valleys and mountains to the west are spectacular. After traipsing along the ridge for a few hundred yards, we found a survey marker but no register. There was a man near the top with a tiny GPS antenna on a very large tripod making a survey for the USGS. He was receiving from eight GPS satellites for a 4-hour stretch. When combined with similar measurements from other sites, the USGS hopes to get 4 millimeter baseline accuracies. There were two other parked vehicles plus a tent in the summit area but we didn't encounter anyone else at that time. Returning the way we came, we encountered a lone mountain biker coming up 5S15. We decided to continue south on 5S15 beyond the dirt road we had used coming up to see if we could find the Tool Box Springs Campground. Sure enough, it soon appeared with another dirt road heading east. We descended on this road and finally came to the spring with a bright shiny spigot. The road ended but a trail continued. Although there was no sign this was the Ramona Trail, after 100 yards or so we came to a fork with the side trail we had used on the ascent. We stayed to the right and continued on down the Ramona Trail.
After a while the mountain biker caught up with us on his descent. He had been up this trail to the Tool Box Springs Campground, gone on to Thomas Mountain, and was measuring the round trip mileage. He promised to leave a note at my car with this measurement. Further down, we encountered a pack of eight mountain bikers on their way up. At the car we found the note which had 13.6 miles as the round trip via Tool Box Springs campground. Our shortcut going up was really not much shorter and we had passed up some excellent cold water. This hike was most enjoyable, particularly with the unexpected outstanding scenery and with perfect October weather.