The Castle Rock trailhead is located 1.1 miles east of the Big Bear Dam on State Highway 18 or 3 miles west of the Big Bear Lake Village. There is limited parking 50 yards east of the trailhead in a turnout on the north side of the highway. The Adventure Pass is not required on the turnout.  There is a small sign marking the Castle Rock Trailhead across the highway.

Although it's not a long hike, the elevation gain is 500 feet, making it a steep climb by any standards. From here its 0.5 of a mile of a steep trail then it levels out for another 0.5 of a mile of less steep trail. Castle Rock is a large 100 ft outcropping from immediately east of the saddle.  This trail offers spectacular views of the lake and an opportunity to see pines, white fir trees and cedars.