Mount San Jacinto is the highest peak in San Jacinto Mountains and the second highest point in Southern California. This summit receives a lot of visitors everyday, facilitated in part by the tram that runs up from Palm Springs to 8,500 feet. The Marion Mountain Trail stays on the southwest aspect of Mount San Jacinto, and apart from the Skyline Trail hike, it is one of the most challenging routes to the San Jacinto summit. The rewards are many, however, as this route offers amazing views and plenty of solitude.
The trailhead is located at at 6,000 feet just north of Idyllwild, and there is a parking lot right across from it. The trail immediately climbs 2 miles through a deep forested area before easing up onto a rolling hill section that leads to Little Round Valley. With every opening in the forest you'll have an expansive view of the Inland Empire that will be below a sea of clouds much of the time. This established trail has lots of creeks and water sources in the spring. It might be dry in the summer time, however, so be prepared to carry water.
The trail merges with the main trail from the tram station just after you pass Little Round Valley, which offers a few primitive campsites and a nearby vault toilet. At the junction , make sure you take the path to the left toward the summit hut instead the trail going back to the tram station. A short hike from the junction there is a stone hut where you can rest and leave some of the stuff that you don't want to carry to the summit. Inside the hut there are four bunks for an emergency shelter.
The summit is just a short scramble from the hut. There are multiple ways to get to the summit, which can get confusing if you try to follow the main trail. Either way, most of the trails will get you to the summit.
In most of good days, the summit plateau will be full with hikers. But the area is big enough for you to catch a breath and enjoy the view of San Gorgonio Mountain, the Coachella Valley, and the Salton Sea on the good day. Once you are well rested, you can make your way down to the car following the same route.