Picnic Rock Viewpoint – Sierra Peak Summit loop from Oak Street 1003-010 Dam

If you're looking for a serious mountain biking challenge in Orange County, the Sierra Peak Summit loop from Oak Street 1003-010 Dam is a demanding 16.3-mile (26.2 km) route rated moderate, with 2449 feet (746 metres) of elevation gain, typically taking around 2 hours and 44 minutes. While the full route name suggests a combination with Picnic Rock Viewpoint, this Komoot tour focuses on the challenging Sierra Peak section, making it ideal for strong intermediate to advanced riders seeking a tough climb and technical descent.

What to expect on Picnic Rock Viewpoint – Sierra Peak Summit loop from Oak Street 1003-010 Dam

This route primarily follows wide dirt fire roads, which can be rutted, steep, and covered in loose rock, especially on descents. As you climb, you'll experience a remote feel, a welcome escape from the nearby urban areas. From the Sierra Peak Summit at 3,045 feet, you'll be treated to panoramic vistas of North Orange County, Corona, Riverside, and even the distant San Gorgonio Mountain. The sustained climbs demand a very good level of fitness, and the steep, technical descents require caution and skill, making this a ride best suited for experienced mountain bikers.

Planning your visit

Given the challenging nature of the Sierra Peak section, ensure you carry plenty of water, especially during warmer months. While specific parking details for the Oak Street 1003-010 Dam trailhead are not widely available, be aware that some trails in the wider area, particularly those within Chino Hills State Park, may require permits or fees. Starting early in the day is always a good idea to avoid the midday heat and allow ample time to complete the loop.

Trail details

• Distance: 16.3 miles (26.2 km)
• Elevation gain: 2449 feet (746 metres)
• Difficulty: moderate
• Estimated time: 2 hours and 44 minutes