Summit Trail to Rock City and Sentinel Rock is a 4.1 mile moderately trafficked out and back trail located near Diablo, CA that features beautiful wild flowers and is rated as moderate. The trail offers a number of activity options and is accessible year-round. Dogs are also able to use this trail but must be kept on leash.
dogs on leash
The hike starts by the south entrance to Mt. Diablo State Park and follows the Summit trail past the Live Oak camping area. From there it's just a short walk to the Rock City area in the park which is marked by a wide variety of rock structures including the so-called 'wind caves'. These were actually formed through erosion by flowing water creating large hollowed-out areas in the sandstone. A prominent feature is Sentinel Rock that stands well above the surroundings and provides a panoramic view from its summit. There are steps carved into the rock and iron railings at key points for safety when climbing to the top.