The most direct hike to Mount Diablo’s summit

I’ve hiked to the summit of Mount Diablo a few times, but I’ve always wondered what the most direct route might be from bottom to top. I’ve only climbed it from the north, and by the most obvious routes, Mitchell and Donner canyons. Both offer good views and varied scenery, but they are roundabout, taking around 14 miles each, and they aren’t immersive, following dirt roads much of the way. Today, Elizabeth and I were hiking with our friends Colin and Brendan and we had to be back by mid-afternoon, a time constraint that gave us just the right opportunity to try a direct route to the summit. [1]

• Start/End: Regency Drive, 37.9221, -121.9269
• Ascent: Back Creek Road, Back Creek Trail, Bald Ridge Trail, North Peak Trail, Summit Trail
• Descent: Summit Trail, North Peak Trail, Prospectors Gap Road, Middle Trail, Meridian Ridge Road, Donner Canyon Road [2]
• Elevation gain: 3,500 feet
• Distance: 10.5 miles
• Highlights: Forested canyons, chaparral, open ridge walking, views, Contra Costa county highpoint

We started at nine in the morning, walking through the valley-oak savannas north of Mount Diablo under a cloudless sky. The air was 52 degrees, still a little cool. The grass had grown quickly in the last few weeks was now nearly knee-high. Scattered all around us and blooming just above the grass were hundreds of yellow buttercup flowers. In the distance a male turkey gobbled and displayed for a group of hens.

We walked over hills covered in woodlands of blue oak and entered Back Creek Canyon. The trees and shrubs became more dense and the air became colder in the canyon’s shade. A small stream, shrinking with the approaching dry season, trickled alongside us. The trailsides were filled with grass and wildflowers, curling orange fiddlenecks, blue lupine, and violet larkspur. Gray pines and cottonwoods rose above it all, their tops as well as the chaparral slopes above them warmed by the rising sun. The flowers, shrubs, and trees in the canyon were so neatly arranged that they resembled a garden. A covey of California quails scurried in the shadows near the stream.

The trail left the canyon and began to ascend toward Prospectors Gap between Mount Diablo and North Peak. The chaparral was like a short forest here, nearly covering the trail. Fragrant bay trees with smooth gray trunks rose above the thicket. They were joined by chamise, whose leaves have evolved into tiny needles that preserve moisture during the hot dry season. Manzanita twisted through the mass of vegetation, its smooth, almost glossy, maroon trunks drawing remarks from everyone in our group. Ceanothus lent color to the otherwise olive tangle, the ends of its branches blooming with white and blue puffs of flowers. Blue witch added color as well with its violet flowers. Manroot vines festooned it all with newly sprouted bright green leaves and shoots of cream flowers, spreading across the forest floor and winding up the slender trunks and branches of the shrubs and hanging over our heads.

As we continued on the Bald Ridge Trail from Murchio Gap, the chaparral grew shorter until we could see right over it. Behind us was Back Creek Canyon and, to its left, Eagle Peak. Beyond them was the delta formed by the confluence of the Sacramento and San Joaquin rivers and, beyond the delta, the huge plain of the Central Valley. Across the valley, 120 miles away, rising above the haze, covered in snow and looking like distant clouds, were the upper elevations of the Sierra Nevada mountains. Ahead of us was Mount Diablo, which always looks bigger in person than it does from a distance.

The grass balds along the trail were filled with wildflowers: baby blue eyes with white centers and baby blue petals, bird’s-eyes gilia also with white centers but rimmed with violet, phacelia and popcornflower in white, wallflowers and poppies in orange, and goldfields in yellow. Painted lady butterflies were a constant presence, stopping to feed at the flowers as they migrated north from the deserts. Bald Ridge Trail offered a commanding view, and I decided that it should make a fine extension of the climb over Eagle Peak. We rounded north of Mount Diablo’s summit, passed through some canyons filled with shady forests, and then took a break at Prospectors Gap.

Towards the summit on the North Peak Trail, flowers lined our path and filled the treeless slopes below us. To the south and east was a green mosaic of grasslands, chaparral, and forests: the rest of the Diablo Range. We made the summit shortly after noon and put our jackets on against the brisk 40-degree wind. Today was a particularly clear day, and we could easily see San Francisco and the Golden Gate Bridge thirty miles away. The wild land around us was entirely green and the forests and chaparral would remain so through the dry season, but the grass would turn blond within a month.

We descended the Summit and North Peak trails that we had taken up. Back at Prospectors Gap, we took the dirt road by the same name, a steep and dusty stretch with little to recommend besides the view. We all lost our footing at least once on the gravel, which would send us skating downhill. Turning onto the Middle Trail, we went back into the chaparral, the intricate mess of shrubs we’d seen above Back Creek. It was a narrow trail and we were mindful of the poison oak, but it also put us closer to the Indian warrior, paintbrush, and shooting stars that adorned the ground below the shrubs, a position from which we could more easily enjoy them.

I pinched off some California sagebrush leaves before we left the chaparral. The leaves aren’t leaf-like at all, but rather delicate gray-green threads whose terpenes smell like spearmint gum. I sniffed them while I walked. When we got back to the blue oak woodlands, it was early afternoon, 64 degrees, and the sun warmed us all. The sun’s light filtered through the grass, making it seem illuminated from within. The shadows from the boles and slender gray trunks of the blue oaks also fell on the grass, becoming diffused and softened by it. The result was a scene of easy pastoral hills glowing in the sun and dappled with shade. Back at our cars, our joints were weary from the quick descent but we were all glad to have taken advantage of a perfect day in the mountains.

Notes
[1] The trails we took aren’t on the Mount Diablo State Park brochure map. Instead, find them on the best map of the Mount Diablo area: the one from Save Mount Diablo, which is waterproof, tear resistant, and covers over 90,000 acres of public land and over 500 miles of trails.

[2] We used a different route on the descent to make a loop, but either can be considered direct since they’re both the same length, about 5.25 miles. I recommend the ascent route.