Mount Diablo, Contra Costa CA


• 4-star hikes
• 8 to 11 mile options
• Moderate & Hard | Gain 2,280 to 3,390 feet
• Clayton, CA | San Francisco Region
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A stone building with a hexagonal tower, constructed from large, weathered sandstone blocks. The tower has tall, rectangular windows framed with dark trim, allowing natural light to enter. At the top, a small lantern room with a domed roof is visible. The building is surrounded by rocky terrain, with patches of grass and shrubs. In the background, rolling hills extend toward the horizon beneath a clear blue sky.
The Mount Diablo Summit Museum on the mountain's peak.

The morning fog blankets the valley below as we ascend, leaving behind the shrouded cities and emerging into brilliant sunshine. This phenomenon perfectly illustrates exactly why Mount Diablo remains a popular destination for Bay Area hikers seeking clarity above the clouds. As the tallest peak visible from San Francisco when low clouds settle over the bay, Mount Diablo offers a reliable escape to sunshine and panoramic views.

The Visitor Center and Museum at Mount Diablo's summit offer refreshments including drinks and ice creams for all visitors, whether they choose to drive to the summit or arrive on foot. The building itself encloses the true summit of Mount Diablo, so be sure to visit the interior if you want to stand on the mountain's highest point.
⬤ 4★ From Rock City   7.8 mi out & back, moderate, gain 2,280 ft
GPX File · AllTrails · Directions GPX?
⬤ 4★ From Sunset Trailhead   4.5 mi out & back, moderate, gain 1,580 ft
GPX File · AllTrails · Directions
⬤ 4★ Mt Diablo & North Peak from Rock City   11.3 mi out & back, hard, gain 3,390 ft
GPX File · AllTrails · Directions
 $  CA State Park fee

We particularly like this trail in spring, when wildflowers are in full bloom and the weather is temperate. The East Bay's characteristic golden hills transform with patches of purple lupine, orange poppies, and yellow buttercups during this season. As with many East Bay hikes, this trail is best avoided during peak summer temperatures, when the exposed route can become uncomfortably hot.

⬤ From Rock City
The Summit Trail from Rock City starts near the Mount Diablo State Park Boundary at around 1,600 feet of elevation. The trail begins as a service road, eventually becoming a narrow single-track as it gets closer to the summit, but surface conditions remain easy throughout. A modest gradient spread over several miles makes the climb feel moderate at worst.

⬤ From Sunset Trailhead
For those looking for a shorter hike, drive further up Summit Road to the Sunset Trailhead, where you may find a parking spot you could start your hike of the Summit Trail from a higher elevation. Although this shortens the Summit Trail, you still benefit from its best features.

A dirt path winds through a gently sloping hillside covered in vibrant green grass. The path leads toward the horizon, where rolling hills are partially shrouded in misty fog. The sky is bright blue, contrasting with the landscape. Two people walk along the path in the distance, appearing small against the vast scenery. The overall atmosphere is serene and expansive, emphasizing the depth and scale of the natural surroundings.
Heading up on the fire road, with little shade.

⬤ Mt Diablo & North Peak from Rock City
Upon sighting the impressive mass of North Peak from the summit of Mount Diablo we decided we had to add it to our hike, and we're glad we did. Our spring hike from the Devil's Elbow trailhead towards North Peak was where we found the best displays of wildflowers by far. Note that the final part of the ascent on North Peak Road is rather steep - we found it harder to come down than go up - so we've categorized this as hard. We recommend high-friction footwear that you trust and a little patience, if you want to hike this peak.

If you would like to hike the trail to North Peak without also hiking the Summit Trail to Mount Diablo, you can park in any allowable space on the side of the road at Devil's Elbow. Expect a 3.5 mile round-trip and 1,100 feet of elevation gain.

A winding mountain road snakes through lush green hills under a clear blue sky. The road curves sharply as it descends, flanked by dense vegetation. Rolling hills and valleys stretch into the distance, their contours softened by a light mist near the horizon. The serene, expansive landscape offers a breathtaking view, inviting exploration and adventure.
The trail narrows, but the views widen as you ascend.

We always advise bringing more water than you think you might need. However, the Summit Trail offers water facilities at two points: along the Sunset Trail and at the summit itself, assuming they are in working condition. Note that in addition to a drinking fountain at the summit, there is also a much better spigot to the left of the entrance to the visitor center, located behind a bench.

Though Mount Diablo State Park advertises an 8:00 AM opening time, the South Gate Road entrance has been known to open early to reduce morning traffic congestion. This can be advantageous for those hoping to start their hike before the day heats up.

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A panoramic view of a mountainous landscape beneath a clear blue sky. The foreground features winding trails cutting through dense green vegetation, leading up to rugged peaks. The distant background reveals rolling hills and valleys, stretching toward the horizon where a small town or city is faintly visible. The natural scenery showcases a balance between untouched wilderness and human settlement, inviting exploration and adventure.
North Peak viewed to the East, from Diablo's summit.

Two hikers walk along a narrow dirt trail on a hillside covered in lush green grass and wildflowers. The winding path leads through scattered trees and shrubs, opening up to a sweeping view of rolling hills beneath a clear blue sky. The hikers, clad in outdoor gear and backpacks, appear to be on an adventurous trek, immersed in the tranquil beauty of nature.
The best wildflower display was on the North Peak trail.

Two towering telecommunications structures stand against a bright blue sky, bristling with antennas, satellite dishes, and network cables. Positioned on rocky terrain, these towers serve as critical hubs for broadcasting and communication. Their intricate framework supports an array of circular and rectangular components, illustrating the complexity of modern connectivity infrastructure.
Radio Towers atop North Peak.

A gnarled tree with moss-covered branches stands prominently in the foreground, its twisted limbs reaching out over a rolling landscape. The hills beyond are blanketed in rich green grass and scattered trees, partially veiled by a soft layer of mist. The fog lends a sense of tranquility, muting the distant contours of the landscape. Above, the sky is a brilliant blue, contrasting with the earthy textures below.
Another view from the Summit Trail.

Tangents:
• Official: Mt Diablo State Park
• AllTrails Public: Mt Diablo from Rock City

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