Rock City to the Summit of Mount Diablo

MODERATE 21 reviews
#5 of 21 trails in

Rock City to the Summit of Mount Diablo is a 7.8 mile moderately trafficked out and back trail located near Danville, California that features beautiful wild flowers and is rated as moderate. The trail offers a number of activity options and is accessible year-round.

7.8 miles 2299 feet Out & Back




mountain biking

nature trips

rock climbing

trail running




wild flowers



From Rock City hike up to the summit. This trial offers scenic views and breathtaking climbs. Although steep in sections, it is a great hike. This park is one of the ecological treasures of the San Francisco Bay Area. Many visitors to Mount Diablo head straight for the summit to enjoy the famous view. Summer days are sometimes hazy, and the best viewing is often on the day after a winter storm. Then, you can look to the west, beyond the Golden Gate Bridge, to the Farallon Islands; southeast to the James Lick Observatory on Mount Hamilton at 4,213 feet elevation; south to Mount Loma Prieta in the Santa Cruz Mountains at 3,791 feet elevation, north to Mount Saint Helena in the Coast Range at 4,344 feet elevation, and still farther north to Mount Lassen in the Cascades at 10,466 feet. North and east of Mount Diablo the San Joaquin and Sacramento Rivers converge to form the twisting waterways of the Delta. To the east beyond Califomia's great central valley, the crest of the Sierra Nevada seems to float in space.

14 days ago

Rock City to Summit via Summit Trail. Hiked this with my 17-year-old son. It was great bonding time, and he was very patient with me. The trail is well maintained, which is nice. However, the trek up was tough for me. It took 3.5 hours to the Summit and 2 hours back down. I would rate it moderate plus some. There are virtually no switchbacks, so you are hiking uphill, albeit gradually, the entire way. Informational signs and center at top were interesting. Plenty of opportunity for bathrooms but no potable water sources between Rock City and the Summit, so come prepared and fill up when you can.

14 days ago

This was a challenging hike from the sandstone formations of Rock City up to the summit of Mount Diablo. This 9.5-mile double lollipop loop hike took 5 hours to complete. Much of the Rock City trail, Summit trail and Juniper trail are along the “Trail Through Time” with its interpretive signs describing 190 million years of geological history. At Rock City we hiked amongst the Wind Caves and climbed up Sentinel Rock before proceeding up the Summit trail. The summit is at 3,848 feet. When we were up there we had rain and it turned into snow. We returned on the Juniper trail passing Juniper Camp and back to the Summit trail.

16 days ago

Awesome.. great views at several points throughout, but the trek itself provides great memories should you go the entire way to the summit,

28 days ago

2 months ago

Great trail however the trailhead and starting point are not clear. Read above comments for best directions.

Plan more time than expected. I accidentally ended up hiking a portion of the trail in the dark. I was prepared with a headlamp however because of the nature of the trailhead not being clear it could be easy to get turned around. Near rock city there is a huge network of social trails, just be aware and take a gps point of where you parked your car.

Incredible views and beautiful around to rock city!! Great diversity of ecosystems and terrain. Awesome summit.

3 months ago

Great hike. Glad we found it on this great Ap.

3 months ago

Get hot not much shade, if any. Drink lots of water. Had a picnic on the return. And loved every moment.

4 months ago

Did the trail today (Sep 2016). Its a moderate trail for seasoned folks. For beginners its a hard trail. Partly because sun beats down on you directly if you pick the climb in morning hours. The park opens late (8:00 AM) and that means you can't attempt the climb early in the morning. I think its better to start the trail in afternoon when sun is on the other side of the hills.

Trailhead and other trail information is sketchy at best. We didn’t buy the $6 parking map at the entrance so I am not sure how it would have helped but the map that comes with brochure (given at the gate when you pay $10 entry fees), and that is also available at the website, is of little help in figuring out Trails and trailheads. Many trails and loops adds to the confusion.

Bring water especially if you plan to start late. I drank 1.5 Ltrs during the trip (compare to 0.5 ltr for mission peak). You will have two bathrooms in the trail before you reach the secondary parking lot (read below).

Started at 8:20 and returned at 12:30. We took breaks at top and some other places.

Park at rock city/Live oak campground which is right off the main road leading to summit. This place is ~1.5 miles from the southern entrance. The parking is small and is distributed between different parking lots/places. Plan to arrive early as we saw few people looking for parking when we came down. The summit trail starts at the Southern Gate entrance I think but there is no parking there. Park rangers will tell you to go to the Rock city to start the climb.

You can latch on the trail right at the parking lot or you can walk down to the main road and go a little way up to see two trails on your left. Take the right one. We couldn't locate the trailhead at parking lot and walked along the main road a little way up before we found the trailhead.

Trail crisscross with the main road couple of times and also runs closer to the main road for some part. Trail also merges with fire trails that are dusty.

Keep looking at the summit trail direction in trail signposts at each junction and keep climbing up. You will pass through a sitting area and cross the road before the real climb without shade starts. This part ends when you hit the main road again.
After that you hit flat paved road for sometimes before you climb a little more and reach what we assumed was a fork for upper/lower summit trail (we can be wrong). There is a large water storage facility here and one bathroom.

After this the climb is steep with single file walk. Keep climbing till you hit the road again. The trail doesn’t crosses the road this time but continues to right for slow downhill walk before the steep climb starts again. You end this stretch again at the main road at a scenic lookout point.

At the scenic lookout you are at the road and can see the summit center at top and a large tower far at left. A short steep climb again and you land back at the road again at the secondary parking lot below the summit center. The road to summit forks here with separate way to up and down. Hike a little up the road, cross to get into an area shade from small shrubs and tree. At this point you can continue via the road to the top too. You are very close. The small climb through the shade leads to a large comms tower and immediately after that the trail ends in the main parking lot at the summit center.

Be there at 8:00 if you plan to climb in AM. That way you can avoid too much sun on the way up.
Bring water but 2 ltrs of water one way is too much. You can refill at the top. 1 ltr one way should be good enough.
Wear hiking shoes. Trail is rough at many places with gravel and lose stones. Many places there is too much dirt.
Bring hats and sunscreen to avoid sun exposure

5 months ago

Great hike. Very challenging, but very rewarding. Bring lots of water! I drank 2 litres on the way up. You can refill at the top.

5 months ago

5 months ago

Always a great hike. If attempting during summer bring a good amount of water

6 months ago

7 months ago


8 months ago

Great workout, lots of flowers!

11 months ago

11 months ago

We had so much fun with the kids!!! They loved climbing all over the rocks and inside. I would brings snacks, water and cleansing wipes!

1 year ago

Wind tunnels are cool! Loved climbing on the rocks. Unfortunately, I didn't complete the trail. I spent a lot of time playing on the rocks.

2 years ago

Headed up to Mt Diablo right after Christmas to work off the food. While my plan was to hike from the start of the summit trail, there's no real parking down there so I headed up to Rock City's lot just after the gates opened and started with it all to myself (came back to find it completely full). The summit route is nothing special as you're pretty much walking parallel to the road though there are some spectacular views out and around the bay area foothills the whole way up. It's also really interesting to see the impact of the recent fires along parts of the trail and the dirty / brush grow back. Obviously nice views up top at the summit visitor's center. Ended up working in the North Summit as well which added a couple miles and several hundred feet of additional gain (you go down to up then do it again) for a longer workout.

3 years ago

We love going up here ;) We haven't done the full loop yet.... We get to distracted by the rock climbing!!! Kids love it up here!!!

4 years ago

Great intro hike for my 3 year old. He loved playing in the wind caves