Mount Diablo Grand Loop Trail

MODERATE 169 reviews
#4 of 61 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
1856 feet



nature trips

trail running




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.

19 days 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!

24 days 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.

1 month ago

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

1 month 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.

2 months ago

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

3 months ago

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

3 months ago

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

4 months ago

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.

4 months ago

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.

4 months ago

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!).

7 months ago

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

7 months ago

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

9 months ago

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.

9 months ago

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.

9 months ago

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.

9 months ago

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.

10 months ago

very nice trail

11 months ago

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.

Sunday, May 14, 2017

Wonderful views and gorgeous wildflowers! A good workout, and clean bathrooms in the camp site.

Sunday, May 07, 2017

Awesome for a weekend hike. Took a few hours, was definitely a little difficult but a great hike!

Tuesday, May 02, 2017

very nice and lush in april lovrd it

Monday, May 01, 2017

Hard! Steep ups and downs. Of course there were the young folk who were running it but regardless it was great! Took me 5+ hours.

Sunday, November 13, 2016

Great trek. Went on a pretty clear day, almost constant views. It was some work though, but well worth it.

Tuesday, November 08, 2016

great views but was longer than 6.2 miles. more like 7.3 miles. so plan for 4.5 hrs.

Monday, September 12, 2016

This hike provided a relatively decent hike, but there wasn't a lot of shade for most of the hike. The scenery wasn't breathtaking, perhaps because of the time of year that I went? I'd still recommend trying it out though, if nit just for a day adventure.

Saturday, September 10, 2016

Gorgeous views of the whole tri-valley area, especially on a clear day.

Saturday, August 27, 2016


Tuesday, June 21, 2016

Gets very steep for a sustained period (some might find it difficult), but the gorgeous views throughout this hike make the incline more than worth it.

Monday, January 25, 2016

Went for Grand Loop and ended up doing The Summit. It was 10 miles round trip. Overall great experience.

Monday, December 28, 2015

Incredibly beautiful hike with amazing views. As other reviewers have noted, it does get pretty steep and there is a lot of going up and down. It is not too bad though if you have good hiking boots. I would not recommend doing this hike in normal sneakers since having boots with some tread on them will make this hike much easier!

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