This is the Mount Diablo’s most memorable hike — the complete climb from base to summit. Because of how steep and rough the trail is, the entire loop takes about 8–9 hours; there just isn’t a lot of trail where you can walk at a normal pace. The first half of the route described here, via Eagle Peak and Bald Ridge, is especially slow and difficult due to the poor condition of the singletrack trails. But it’s worthwhile because of how scenic and interesting it is.
The loop, especially the upper half, features striking views of the Bay Area and Central Valley that are much more dramatic than anywhere else in the East Bay. The hike is made even more interesting by the unusual vegetation; the slopes of Mount Diablo, especially the northern slope, really don’t look like any other place in the Bay Area. On cool spring days, when the vegetation is green and flowers are blooming, it’s really quite attractive.
This loop can be split into two hikes that are still pretty challenging. The lower half, from Mitchell Canyon to Murchio Gap, is 8.5 miles long with 2180 feet of climbing and would get a two star rating. The upper half, starting at Juniper Campground, descending to Murchio Gap, and then climbing to the summit, is 7.5 miles long with 2010 feet of climbing, and would get a three star rating.
The route is surprisingly popular given how difficult it is — on a nice spring day you might pass a group of hikers every 2–3 minutes.
Most of the route is exposed to the sun and can get really hot, so this hike should be avoided if the forecasted high for Clayton is over 85 degrees.
Like everywhere on Mount Diablo, there’s a lot of poison oak along this route, although it can normally be avoided. Hop trees are also common throughout the hike; the leaves of this tree look a lot like poison oak but they don’t cause a rash. Hop tree leaves are usually a little smoother and narrower and not lobed, while poison oak normally doesn’t look like a tree in this area.
Park at the Mitchell Canyon Visitor Center and take Mitchell Canyon Road, just to the right of the visitor center. The hike gets off to a great start as the road runs through attractive oak woodland. After just a few yards, turn left onto Oak Road, which sets the tone of the hike by immediately beginning a steep climb. Turn right onto the singletrack Mitchell Rock Trail. Here, the oak woodland quickly gives way to an unusual landscape of grass-covered hills dotted with Coulter pines. This species, which produces the biggest cones of any pine tree, don’t normally grow in the Bay Area; it’s more commonly found in the mountains of Big Sur and Southern California.
There’s a sign for Mitchell Rock, a not-very-exciting lump just to your right. This is different from the Mitchell Peak shown on the USGS topo, which is a more prominent peak a little further up.
The trail comes to the base of a huge, steep hill; as it starts climbing the hill, the landscape changes to scrub. The next landmark is Twin Peaks, a small rock formation with a great view of the valley to the north. This is where the scenic views start to get really good.
Up to this point the trail has been wide and well maintained, but as it begins to climb up a steep ridge to Eagle Peak, it becomes narrow and somewhat rough. As the trail goes through some large switchbacks, it passes through a narrow tunnel through dense, tall scrub. Although the trail is heavily used, it’s also overgrown enough that you might have to crouch down in places. This is actually pretty typical of Mount Diablo singletrack. At least the chaparral offers some shade, and the effort of pushing through all the brush and trying to avoid the poison oak takes your mind off all the climbing.
As the trail approaches Eagle Peak it breaks out of the chaparral, providing the most spectacular views yet. After Eagle Peak there’s a very steep 300 foot descent on a rough trail with lots of loose gravel. The rugged north side of the peak is oddly barren, looking more like the Southern California desert than the Bay Area. The trail bottoms out and then climbs a scrub-covered ridge to Murchio Gap; this part of the trail can be quite brushy.
Murchio Gap is just over halfway up the mountain, with 2040 feet of climbing done and 1760 feet to go. The second half, though, feels a lot more difficult. Continue straight ahead on the Bald Ridge Trail, which climbs steeply along a ridge that is, as the name suggests, blissfully free of brush for the first half-mile. Besides making hiking a lot easier, the lack of tall scrub means that are some great views of Clayton and the surrounding hills. Unfortunately the trail eventually begins a steep climb through a narrow, overgrown tunnel cut through a mixture of tall scrub and groves of small, scrubby trees. There’s a lot of up-and-down and in places the trail is so steep that it’s hard to keep keep from sliding back down the hill. There’s also a lot of poison oak but it’s not too hard to avoid. You could avoid this difficult stretch of singletrack by taking Prospectors Gap Road instead of the Bald Ridge Trail, but the road is also really steep and less scenic.
Prospectors Gap marks the end of the claustrophobic, overgrown tunnels of scrub; for the rest of the hike, the trails are all blissfully wide and well-maintained. They’re still somewhat steep, though.
As the North Peak Trail curves around to the north side of the mountain, some outstanding views of Morgan Territory and the Central Valley open up, among the best of the entire hike. The views are especially dramatic because at this point you’re far above all the other hills around Mount Diablo.
After Devil’s Elbow, there’s one last push to the summit area, which is always busy with tourists and cyclists. I like to take the Mary Bowerman Trail around the summit; it’s refreshingly level, and the views are actually better than the view from the summit. Finally, take the short trail to the summit, where there’s an observation deck and a visitor’s center with a little gift shop. The actual summit is inside the visitor’s center.
Because it’s mainly on dirt roads, the descent is less scenic than the ascent, but at least the road is wide and well maintained. You still can’t hike at a normal pace because the roads are steep and gravelly, but it’s still faster and easier than the trails.
The Juniper Trail starts at the end of the large picnic area and overflow parking lot. It descends through a woodland of short scrubby trees, then through a shady bay laurel grove, to Juniper Campground. Take the paved road through Juniper Campground to the start of Burma Road, which is one of the few flat stretches on the hike and offers some nice views of the San Ramon Valley.
Turn right onto Deer Flat Road, which descends through attractive pine-dotted meadows. The road isn’t especially steep as it zig-zags down the hillside, but it gets a bit steeper after it crosses Meridian Ridge Road and turns into Mitchell Canyon Road. The upper half of Mitchell Canyon Road is somewhat dull, but at least the road is in good condition and much easier to hike than the singletrack. When the trail reaches the bottom of Mitchell Canyon and levels out, the surroundings change from chaparral to pleasant streamside woodland. The scenery continues to get progressively better as the trail approaches the visitor center, changing to oak-dotted grasslands near the end.
© 2015, 2021 David Baselt