Rock City to the Summit of Mount Diablo

HARD 105 reviews
#6 of 31 trails in

Rock City to the Summit of Mount Diablo is a 8.1 mile moderately trafficked out and back trail located near Danville, California that features beautiful wild flowers and is rated as difficult. The trail offers a number of activity options and is accessible year-round.

8.1 miles
1971 feet
Out & Back




nature trips

rock climbing

trail running




wild flowers



no shade

no dogs

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.

1 month ago

4 months ago

This is a HARD trail, very little shade, and consistent inclined on the way up. Don't go on a hot day

5 months ago

Used to hiking in the PNW, so I'll be honest here: was no expecting the heat and lack of shade. It was a tough hike that did offer a nice (albeit brown) view of the surrounding landscape in 360. If you look closely you can see SF from the summit, though not as nice a view as the summit of Mt. Tam.

Warning: there are water spouts along the trail. Don't drink from any of them except the one at the summit in the parking lot.

5 months ago

A lengthy and a moderate level hike. Not so crowded for a 4th of July weekend. Most of the trees and flowers were dried and it was not a scenic hike.

8 months ago

Try not to get yourself to tired at Rock city, before this hike, as it gets pretty steep in parts. "a trail through time" is nice but a little narrow do to poison oak. the mountain is covered with wild flowers and other blooms this year.

9 months ago

If you park near rock city which that is where your GPS will take you, there isn't very much of a hike. The trail was more touristy, so expect alot of people. It was nice when you're alone and the trail veers off here and there. The main trail is the "trail through time" and is pretty much the main trail. There are some if you go opposite of Rock city. It's nice for a first time visit, but I probably won't be going again. And it's also in a state Park, so expect to pay $10 at the gate and a lot of bike riders on the road. Very much a main stream trail

10 months ago

One word: amazing! Took the Pittsburg trail up to the red rocky summit with a beautiful overlook. I am always near Mount Diablo and I will do this hike again.

10 months ago

Rock city is awesome!!! Big rocks to climb everywhere! The hike up to the summit is a little hard but worth it when you get to the top. 360• view of the Bay Area

11 months 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.

11 months 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.

11 months ago

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

Thursday, October 27, 2016

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.

Sunday, October 09, 2016

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

Sunday, September 18, 2016

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

Monday, September 12, 2016

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

Thursday, August 11, 2016

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.

Wednesday, July 20, 2016

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

Monday, May 23, 2016


Monday, May 16, 2016

Great workout, lots of flowers!

Tuesday, January 19, 2016

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!

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