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Mount Diablo Grand Loop Trail

MODERATE 25 reviews
#5 of 18 trails in

Mount Diablo Grand Loop Trail is a 6.1 mile moderately trafficked loop trail located near Clayton, CA that features beautiful wild flowers and is rated as moderate. The trail offers a number of activity options and is accessible year-round.

6.1 miles 1755 feet Loop



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.

13 days ago

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.

15 days ago

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

29 days ago


1 month ago

2 months ago

3 months ago

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.

7 months ago

8 months ago

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

8 months ago

8 months ago

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!

9 months ago


9 months ago

11 months ago

Great hike with awesome views! Gets steep in some places so watch your footing. The geology of Mt.Diablo is facinating! But you see more of it on the trail through time (I was planning on completing that hike but plans change). It gets hot and there's minimal shade so avoid going on a hot day. The views are incredible! If it's clear enough you can see the sutro tower in SF. Beware: poison oak and tarantulas present!

1 year ago

Take the grand loop and have lots of water in your backpack. Awesome trail with terrific views.

1 year ago

Great Hike! If you do the loop in a clockwise fashion it is more difficult that counterclockwise. When you do the loop going clockwise be careful once you start the uphill section at Murchio Gap. It is narrow, steep, and has a lot of loose gravel. Just before before you get to Prospectors Gap you come to a look out that is a great place to take photos or just enjoy the view. The rest of the way is a little uphill but the big stuff is in your rear view now.

1 year ago

March 2015
Weather: windy and cold at peaks, sunny with slight breeze for most of the hike, shade was rare (approx 1/3 in shade)
Gear: do-able without hiking shoes or shoes with no grip, a camel pack of water ~2 liters was enough, hat and tons of sunblock
Trail: more inclines than anticipated, the trail changes often between sand dirt and rocks, no poison oak risk if you stay on the trail, there is poison oak on the sides of the trail

Here are the directions we followed for the Grand Loop:
- Juniper Campground Site #23 Look for wooden fence marker for DEER FLAT ROAD
- DEER FLAT ROAD for 0.75mi (uphill)
- Right onto MERIDIAN RIDGE (downhill)
- MERIDIAN RIDGE comes to a junction with 2 trails
- ATTENTION: Pick the one on the far right, narrow path, steep uphill = BALD RIDGE TRAIL. Does not stand out immediately.
- BALD RIDGE TRAIL for 1.5mi (up and downhill)
- Right onto NORTH PEAK TRAIL toward summit for 1mi (uphill)
- Reach DEVIL’S ELBOW (great photo op)
- Walk to the back of lot and descend to JUNIPER TRAIL
-Left to stay on JUNIPER TRAIL at trail marker
- Stay on JUNIPER TRAIL for 1mi to get back to car (downhill)

1 year ago

Great Hike with gorgeous views. Park at Juniper Campground. If you walk though the campground, you will start at the deer flat trail head, which has a bunch of ups and downs in the beginning, and a bunch of steep climbs 3/4 of the way to the summit. Once you get to the top, you have a fast descent back to the parking lot.

If you go via the Juniper Trail at the immediate right of the parking lot, you'll have a quick steep climb to the top, with a long, slow decent, and then the various ups and downs.

I really liked this hike. Some of the steep climbs are pretty rough, so you better be in shape!

1 year ago

I really enjoyed this hike today. I will say, however, this loop trail is very challenging. I started my hike in the Michael Canyon parking lot. The first couple miles is relatively flat. But once you get to about mile three, the honeymoon is over. At this point, there is a significant incline almost all the way to the top (About 2-3 miles). Coming down the backside of this climb is very tricky...lots of loose gravel, which makes for some slipping/sliding. Overall, I would highly recommend this trail for anyone who is looking for a good workout. Of you don't like incline hikes, you definitely don't want any part of this hike.

2 years ago

I did an extended 18 mile trail run from this starting point. It was 4.5ish miles up to where I turned off onto the Burma Trail for another 5.5 miles then ran/hiked back. This is not for inexperienced hikers or trail runners because the climbs and descents can be brutal. Layer your clothing too because when you're on the rim paths, the wind can suddenly kick up and it gets cold. Take liquids and food for long runs and hikes because there are no resources on the trail.

Probably the most consistently gorgeous trail run I've done! Loved the views...even though the climbs were ouchie! LOL!

2 years ago

I would rate this hike as difficult due to some very steep sections, but the views are amazing every step of the way and are your reward for taking this hike.

The drive up is a little scary due to all of the cyclists - with few kick-outs, you have to really be sure before passing or being passed by on the long windy road to the top.

The Grand Loop took us a bit under 3 hours. We started before 10AM and were practically alone for the first half of the hike. We passed a couple of mountain bikers along the road to Merchio Gap and by the time we got to Summit trail, the parking lot was full and the top of the mountain was crowded.

Bring LOTS of water. There is little cover and you will want to stay hydrated for the steep sections. A lot of hikers had poles. If I were to do this trail again, I would use them.