Thomas mountain was the first hike I've done in California. The first 3.5 miles of the trail, to toolbox springs, is a nice, moderately difficult hike up the foothills of the mountains with plenty of cool views of the San Jancinto Mountain range. My girlfriend and I stayed overnight just outside of toolbox springs and got up to summit Thomas mountain. Toolbox springs is a big developed campsite (no fun for backpackers or other who want to get away) and the trail to Thomas mountain is a big dirt road with plenty of potholes and traffic (we saw three trucks). Watch out for deep snow in January. The view from Thomas was pretty beautiful, with a near 360 view of the surrounding peaks and valleys. There are campsites on top of Thomas, which would probably be really neat to stay at. The trail was a nice starter for our dog, with very little foot traffic (We saw only three other hikers on the last day). Beware, though, if your dog has a palate for horse dung. It's EVERYWHERE. All in all an okay trail, at least for the first part. Oh, and bring plenty of water, because the water at Toolbox tastes (and looks like) rust. Yeck!