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Mt. Diablo State Park: Wildflowers, Vistas, Rock Climbing And More
Mt. Diablo

Mt. Diablo isn’t the tallest peak in the nine-county San Francisco Bay Area.

Its 3,859 summit isn’t the tallest. There are seven peaks that eclipse it with Mt. Hamilton’s 104-foot higher neighbor Copernicus Peak’s 4,354-foot summit east of San Jose topping the list. It’s not even the tallest hike-able peak based on accessibility. That honor goes to Mount Saint Helena out of Calistoga at 4,327 feet.

So why is Mt. Diablo so special?

A little bit of it has to do with its spectacular view shed. You can see much of the Bay Area, virtually the entire Delta, much of the middle of the Great Central Valley, the Farallon Islands 30 miles outside the Golden Gate, and on a clear day after a winter storm you can make out Lassen Peak — the last volcano to erupt in California (it was back in 1915) — some 181 miles away. Altogether on a clear day you can see 80,000 square miles that are part of 35 counties representing 60 percent of the state.

Some of it has to do with the various ways of reaching the summit — via car, by bicycle, or on foot.

It also has to do with the fact there is more than one trail that will take you to the top.

But what really makes Mt. Diablo special is the vast open space that has been preserved that not only harbors all sorts of animal life plus more than 200 bird species and in excess of 400 flower species but offers extensive recreational use. You can hike, camp, walk your dog, explore, explore unique rock and geologic formations, horseback ride, picnic, drop in on the annual tarantula festival, or simply enjoy a leisurely drive to the summit among other things.

The best part is Mt. Diablo is more than just a 20,000 acre park. Thanks to efforts of groups such as Save Mount Diablo the state park is part of 90,000 plus acres of preserved land strung together in a patchwork quilt.


Foggy Sunday hid the Central Valley

The spectacular vantage point to see much of Northern California was hidden for the most part Jan. 19 when I did my first Diablo hike of 2020. That’s because tule fog covered the Central Valley in fluffy waves of grayish white stretching from the snow-capped Sierra to the base of the mountain below hiding the twisting Delta where the Sacramento and San Joaquin rivers converge.

Mt. Diablo — without a doubt — has one of the most impressive view sheds in California, if not the continental United States. In terms of most people being able to enjoy 100-plus mile views in all directions, you will be hard pressed to find a place on earth that matches Mt. Diablo.

And perhaps no times are the views of the Great Central Valley, Bay Area and beyond as clear as they will be in the waning days of January and the month of February thanks to rain and windy days.

But there’s much more to the 20,000-acre Mt. Diablo State Park whose South Gate entrance is just an hour away from Manteca by car than million dollar views from the summit of its namesake peak with an elevation of 3,849 feet and a prominence of 3,109 feet when viewed from the east from Manteca, Lathrop, Stockton, Tracy, Ripon, and Lodi.

The drive to Contra Costa and through the town of Danville to the South Gate entrance road takes about an hour or so. Once you pass the old South Gate entrance along the park’s boundary at 570 feet this time of year you typically are looking down on valleys stuffed with fluffy fog ringed with green hills reminiscent of a lush spring in Ireland. In a month or so, the hills will revert to burnt gold studded with countless oaks.

In the coming three to four weeks wildflowers will start blanketing the hills, making a hike along the extensive trail system teeming with wildlife and distinctive rock formations even more pleasant.

It is why now is the best time to check out the highest peak jutting upward on the horizon as you look toward the Bay Area. And that is true whether you decide to drive all the way to the peak, bicycle up it or hike.


Rock City is popular destination

If you’re into hiking and not driving to the summit, a good starting place is at Rock City, about three quarters of a mile past the entrance station and at about 1,400 feet. The somewhat longer Summit Trail hike starts with a marked dirt path just north of the final home where Mt. Diablo Scenic Boulevard morphs into South Gate Road. The Town of Danville and the state park system has eliminated all roadside parking in the area.

Rock City with its numerous rock formations, Indian grinding rocks, and numerous short trails along with camp sites and picnic areas is the most popular destination in the park except for the view from the top.

It is not too difficult to find the Summit Trail. Even if for some reason you miss the sign posts and believe you are lost, you really aren’t since the Summit Trail and the road to the top weave their way to the summit. The trail itself is a collection of single-file paths, fire roads, and short stretches of access roads.

It typically takes almost two hours on the dot to cover the 2,400 or so net gain to the summit. Thanks to the road and trail crossing more than a few times, you can park even higher up or depart from campgrounds at 2,200 and 3,000 feet.

After summiting Mt. Diablo I rarely resist tackling North Peak (elevation 3,557 feet) topped with transmission towers. North Peak taunts you to try it as it stands a little over a mile away as the crow flies dominating the view to the east.


Summit museum open from 10 a.m. to 4 p.m.

On the way to North Peak is a seventh-tenths of a mile trail to Mt. Olympia (2,964 feet).

North Peak, though, isn’t for the faint-hearted. A lot of casual hikers will give up ascending the access road long before it gets to a stretch near the top that requires slow, sure-footed moves for a hiker while four-wheel drive vehicles would find it a struggle.

A number of Mt. Diablo regulars say they hike — or jog — the North Peak trail to the point where it is in the gully between the two points to access a variety of trails that wander back to the lower elevations into unspoiled territory away from cars.

There is no water on the trail so keep that in mind. Sunscreen is also important most of the year.

The Summit Building and Museum is open from 10 a.m. to 4 p.m. There is an observation deck complete with coin-feed stationary binoculars. If you have binoculars bring them instead.

Rock climbers like Castle Rock with its numerous climbing rocks. Fossil ridge offers close-up looks of fossils preserved for hundreds of thousands of years.

If you opt to drive to the top, be prepared to share the road with plenty of bicyclists.


Plenty of hiking options

If you’re into hiking the state park has 37 established trails ranging from 3.6 miles to 27.6 miles in length with more than 200 miles overall of trails and dirt roads.

If you’re into bicycling it’s tough to beat the grind of the 10.3-mile climb from the park boundary in Danville to the Mt. Diablo summit parking lot and the exhilarating downhill that follows.

If you’re into wildflowers there are 20,000 plus acres that will start blooming in the coming weeks and continue in waves as early bloomers give way to flowers that prefer hotter temperatures. Nature shows off her colors in a typical year well into May.

If you’re into rock scrambling and basic rock climbing the sandstone rock formations compete with miniature turrets, caves and grottos in Rock City 3.3 miles after you cross into the park via South Gate Road is tough to beat.

If you’re into camping, horseback riding, mountain biking, or just enjoying a lazy day in a natural setting you can do that as well.


A geological wonderland

And if you’re into geology the forces of the North American and Pacific tectonic plates brushing up against each other have created an outdoor laboratory.

A short geological lesson: Mt. Diablo at 3,835 feet wasn’t always that high. Some 4 million years ago, volcanic rock beneath 161 million years of sedimentation from the North American tectonic plate forced its way between that plate and the Pacific tectonic.

At first the peaks of the Diablo Range were low and gently rolling hills. But as upward pressure continued it thrust sedimentary levels up as an angle. You can visually see cross-sections of millions upon millions of years of the handiwork of nature’s forces throughout the park.


Things to keep in mind

Some words of caution. Take plenty of water when you hike plus let someone know where you are going and when you will return. Keep in mind cell service doesn’t exist in many areas of the park. Trail maps are a plus.

There is plenty of poison oak so keep on the lookout when you’re walking narrow trails or cutting cross country. Ticks can be an issue from fall to spring in grassy areas. Be sure to check yourself and children frequently.

I’ve only come across one rattlesnake at Mt. Diablo State Park and it was sunning on a rock 12 feet below the trail I was on. I’ve had close encounters with rattlers elsewhere. Just keep in mind they won’t attack unless they are cornered or disturbed. That said it is real easy to keep your distance.

Mountain lions are rarely sighted on Mt. Diablo. The only place I’ve ever “encountered” one was in Death Valley walking along the lip of a canyon some 80 feet above me. I was enjoying Mt. Diablo State Park with another hiker one time when a bobcat scrambled across our path near the Regency Drive access point.

The absolute best excuse to pencil in a trip to Mt. Diablo in the coming months are for wildflowers.


Wildflowers you can see

A few of the native wildflowers below Mt. Diablo include:

* California Golden Poppy: It is almost a year-round flower on Mt. Diablo with most blooms between March and October below 3,500 feet in grassy areas. The biggest treat is mass blooms typically blanketing hillsides along the North Gate Rad between mid-April and the early part of May.

* Manzanita: The common shrub offers delicate pink or white blooms from December to March in delicate bell-like shapes. The rain and cooler weather may prolong the blooms until the end of March.

* Chaparral Currant: This shrub also features pink flowers and has been in bloom since December at the lower elevations. Expect to see them in bloom through about May near Mt. Diablo’s summit.

* Milk Maids. The white flowery plants are part of the Mustard family and will be in abundance until they start fading away in May.

* Indian Warrior: The striking reddish leaves start popping up among the pines at the lower elevation in March and then finish up blooming in April near the summit.

* Shooting Star’s Mosquito Bills: The pink flowers appear in mass from mid-February through April.

* Mountain Violet: The purplish flowers are common from March to May.

* Johnny-Jump-Up: Also found from March to May, they can’t be missed thanks to deep yellow blooms with streaks of black.

* Jim Brush: The member of the California Lilac family offer blue blossoms from late March to early May.

* Buck Brush: A personal favorite of mine due to its scent that smells like freshly popped popcorn, it is now in bloom through late May.

Those are just a few of the wildflowers you can find on Mt. Diablo.

In reality, you don’t need to soak up wildflowers to have a visual feast visiting Mt. Diablo. This time of year the hills are a lush green compared to the golden hues of late spring, summer, and fall.