Four Peaks loop

The Four Peaks loop typically starts from the Donner Canyon Road & Back Creek Trail Access point. Parking is available within Mount Diablo State Park, but it's advisable to arrive early, especially on weekends, as spots can fill up quickly for popular trails like this one.

Yes, Mount Diablo State Park charges an entrance fee per vehicle. You will need to pay this fee upon entry to the park. No specific hiking permits are generally required for day hikes on the Four Peaks loop, but always check the official park website for the most current regulations.

Dogs are generally allowed on paved roads and in developed areas within Mount Diablo State Park, but restrictions often apply to specific trails. It's best to check the official Mount Diablo State Park regulations regarding dogs on trails before you go, as some sections of this loop might not permit them.

The best time to hike the Four Peaks loop is during the cooler months, from late fall through spring. Spring offers the added beauty of blooming wildflowers. Summers can be extremely hot and exposed, making the hike significantly more challenging due to limited shade. Winter can be pleasant, but be prepared for potentially muddy conditions or even snow at higher elevations.

The terrain is diverse and demanding, featuring steep ascents and descents on both singletrack trails and fire roads. Expect sections with loose gravel, which can make footing tricky. Some parts, especially leading to Eagle Peak, can be rough and overgrown. The route is largely exposed, so sun protection is crucial.

This is a very challenging and strenuous hike. While some experienced hikers might complete it in 7.5 to 10 hours, it's not uncommon for the entire loop to take 10-16 hours, depending on your pace, fitness level, and the specific route variations you take. Plan for a full day on the trail.

The loop is named for the four prominent peaks it summits: Mount Olympia, North Peak, Mount Diablo, Mount Diablo Summit, and Eagle Peak. From these summits and various viewpoints, you'll enjoy spectacular panoramic views of the Bay Area, Central Valley, and on clear days, even the Sierra Nevadas.

Yes, the Four Peaks loop utilizes sections of several other trails within Mount Diablo State Park. You'll find yourself on parts of the ADT - California - T - Seg 7, Mokelumne Coast to Crest Trail, Falls Trail Loop, Bald Ridge Trail, North Peak Trail, and George Cardinet Back Creek Trail, among others.

Given the trail's length, difficulty, and exposure, you should bring plenty of water (more than you think you'll need), sun protection (hat, sunscreen, sunglasses), sturdy hiking boots with good ankle support, high-energy snacks, and a map or GPS device. Trekking poles can also be very helpful for the steep ascents and descents.

Yes, Mount Diablo State Park offers many trails suitable for various fitness levels. If the Four Peaks loop sounds too strenuous, consider shorter, less challenging hikes within the park. For example, the Mary Bowerman Trail Loop near the summit offers great views with less effort, or explore trails around the lower elevations for a more moderate experience.

Water is typically available at the visitor center located at the Mount Diablo Summit. However, this is a long and challenging hike, and you should not rely solely on this as your water source. Carry ample water with you from the start, especially during warmer months, as other water sources along the trail are limited or non-existent.