Mount Diablo Grand Loop Trail

MODERATE 182 reviews
#3 of 69 trails in

Mount Diablo Grand Loop Trail is a 6.7 mile moderately trafficked loop trail located near Clayton, California that features beautiful wild flowers and is rated as moderate. The trail offers a number of activity options and is accessible year-round.

6.7 miles
1,856 feet


nature trips

trail running


bird watching



wild flowers


no dogs

The Grand Loop offers a bird's-eye view of the Bay Area, and sometimes glimpses far beyond, of the Farallon Islands, Mount Lassen, the Sierra Nevada, and the Santa Cruz Mountains. It's also a a hotspot for wildflowers in the spring.

15 days ago

I would recommend parking at Mitchell Canyon where they have restrooms, picnic area, ranger station and trail maps. I would NOT park at Regency drive. Limited parking on the bottom of a residential DEADEND street. Gets really congested and nightmarish to get out of. zero restrooms, trash cans or water.

19 days ago

This is a hard hike, not moderate. My husband and I hike regularly but usually do shorter hikes. This was challenging for us. January weather was beautiful, about 60 degrees, but a lot of this trail is exposed and in the sun. Bring sunscreen. Deer Flat and the beginning of Meridian Ridge are flat and downhill. Pretty much everything after that is steep incline. Loose gravel on a lot of the trail. We completed in about 4 hours with a LOT of stopping. Views are breathtaking. Will definitely return to Mount Diablo, not sure we'll be doing this hike again, though.

1 month ago

Great hike, amazing views. Less traveled than many routes on Diablo. We had wind gusts up to 60 mph, which is unusual, but made it more adventurous. Would strongly recommend for someone who wants a decent workout in a relatively short hike.

1 month ago

Just got back into hiking before Thanksgiving and this was a great hike. Challenging; but, wasn't too overwhelming. Took a little detour to the observation center to see the view. That made it worth it. Clear day and beautiful views. Was about 34 degrees when we started. Wore layers. Should have brought gloves and something to cover my ears; but, wasn't horrible. Will definitely do this one again!!

1 month ago

Loved this hike. I thought it was more of a hard hike than moderate. The incline was pretty steep.

5 months ago

The hike was awesome!!!
I hike with my dad,and we had fun with great views.
And if you want to go drive to mountain,you need to pay 10 dollar, but hike was that much worth.

5 months ago

Very hot day, hike with my 11year old son. The trail was easy walk with great view. Path was very stable, just fun!

5 months ago

This was a great hike... just strenuous enough but not a total killer for one of medium ability... thanks to previous reviewers... it did take 4 hours when you factor in occasional breaks and lunch and a stop to explore visitor center. Thanks also to this app for helping me navigate... made a few wrong turns but was able to quickly correct thanks to gps. The sometimes mediocre signage is why I am only giving 4 stars. Could be greatly improved upon. Bring plenty of water and plan for a work out. I imagine the view can be spectacular but alas it was too smokey when I did the hike to see all that was there.

7 months ago

So thankful for all of the shade! Definitely saved me on a hot morning. The uphill climbing was a littleeee rough but the views at summit made it all worth it!

7 months ago

A very nice hike, very nice views on the path. It was a bit hot so don’t forget to bring enough water! Especially with kids.

Great hike for 360 views around mnt. Diablo. Started at 9:30 from Juniper Campground (note it takes 25-30 min to drive the curvy road full of bicyclists on a Saturday morning from the park entrance.) I took 4 hours 45 min including 30 minutes to explore the summit. Trails are steep at times but never for too long.

8 months ago

Great hike! Lots of shrubbery needs to be trimmed. You end up going downhill for the first mile and a half then making your way up the back loop. Hike ends with an easy downhill. Start early - the trail started to get busy with Juniper Spring hikers around 12, since the trail overlaps.

9 months ago

Fantastic hike today! I did it clockwise from Juniper Campground. There are some steep parts with loose gravel on dirt that I wouldn’t want to do going downhill, so I recommend clockwise.
There were so many gorgeous wildflowers! I also saw a coyote. I added on the spur trail to the summit, since I’d never been there.
There’s a lot of poison oak. Most of the trail is wide enough that it’s easily avoided, except for the Bald Ridge section. Wear pants and long sleeves! It goes up to shoulder height.
Most of the trail is exposed, and it felt warm even though it was under 60 degrees when I started. Wouldn’t want to do this on a hot day. I’ll definitely do it again, though!

9 months ago

This was a great hike and a great time of year to do it.
Everything was still green and blooming. The marine layer kept it cool today.
We did the hike counter clockwise and added the Juniper and Summit Trail loop to it.

10 months ago

Awesome hike. Do the Moses Ridge out and back off the Juniper Trail (adds 0.8 miles) for some more great views.

10 months ago

We did this clockwise, starting at the parking area in the back of the Juniper campground. Views are amazing as you make a full circle around the summit of Mt. Diablo. There are some rather steep sections in this loop. The Bald Ridge Trail in particular is like a roller coaster, twisting and turning and steeply climbing up and down, but there are some spectacular view points in that section. It tooks us about 4 hours with a lunch break at the summit.

11 months ago

Lovely trail with views. Feb and March seem like a great time to go to avoid the heat and rattlesnakes.

Sunday, January 28, 2018

Bald Ridge is a narrow path with brush - Runners may want to use Prospect Gap and Meridian Road paths

Saturday, January 27, 2018

The views were great! The trail markers were a bit confusing so make sure you talk to a Park Ranger before starting

Wednesday, January 10, 2018

Me and my partner came here not knowing where the trail started. We parked at the base of the mountain, took a map and started. Obviously it's a mountain so lots of inclines. It ended up being a whole day hike and it was dark by the time we made it back to our car. Really nice views at the top! We spotted a lot of deer on our way back.

Wednesday, January 03, 2018

Loved this hike, but make sure you have good hiking shoes. Only reason it’s not 5 Stars for me is the fact that you start the hike with a steep up hill AND end it with a steep up hill. Very beautiful though.

Sunday, December 31, 2017

Loved! Great work out and a nice mix of up and down. The trail was really steep and loose at points so make sure you’ve got good shoes (and you clip your toenails!).

Thursday, October 12, 2017

Good hike, a little mundane along the fire road though.

Friday, September 22, 2017

Goes up and down, can be quite steep. If you are in normal shape you should be able to do it without a problem.

Sunday, August 20, 2017

The first mile and last 1-2 miles are pretty tough up hill. In between there are some short steep climbs but it's mostly down hill, which becomes pretty strenuous and is very difficult/dangerous without hiking shoes. The views are nice but not my favorite hike.

Wednesday, August 09, 2017

If you have even a tinc of patella-femoral issues, it might be good to sit this one out - a lot of up/down. That said, it's all sublime. My son and I made a point to stop and take things in - as a 4th-grader, he was a bit disappointed by the lack of devils, but got over that pretty smoothly. Can't beat the vistas and knowing that Eugene O'Neill probably hiked at least a portion of the same trails back in the day. Highly recommended, but bring plenty of water - you'll need it with some of those fire roads at the end.

Monday, July 31, 2017

I brought over 40 oz of water and it wasn't enough (it was in the 80's) but luckily there were water fountains at the top. The first couple miles of this hike are a breeze but it gets significantly hard/steeper for the next few miles. I run regularly but was still very sore the next day. It was a fun hike but not as easy as some other trails rated 'moderate' on this app.

Friday, July 28, 2017

Awesome, varied trail with some excellent sweeping views of the bay area. Doing the whole loop in 90+ degree weather is certainly a challenge for the less experienced hikers. Bring plenty of water and prepare to be handsomely rewarded for the endeavor with a visual feast of nature and wildlife.

Thursday, July 06, 2017

very nice trail

Tuesday, May 23, 2017

We started from Juniper camp ground. It's hard and no shade at all. There are a lot of gravel which makes it tough will climbing down.

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