Skip to main content

November Bay Trip Part 2; Mount Diablo State Park

By
The Diablo Range is a long inland Californian Coastal range stretching from the Carquinez Straight near San Francisco Bay south to the Temblor Range roughly bounded by California State Route 46. I've been down pretty much almost every major road in the Diablo Range over the years, some are among my favorites like CA 198 and the Parkfield Grade.  There has been two major roads I had left to explore in the Diablo Range that I've been meaning to get off my list of things to do.  First is Idria Road to the Idria Mine and the Summit Road of Mount Diablo in Mount Diablo State Park.






After jumping onto I-580 after completing I-205 I took I-680 north to Diablo Road.





I took Diablo Road to Mount Diablo Scenic Boulevard which runs to the southern entrance of the State Park becoming South Gate Road.







Mount Diablo is a 3,849 peak in the northern Diablo Range.  While not the tallest peak in the Diablo Range Mount Diablo has a prominence of 3,109 feet which gives it one of the widest vistas in all of California.  Mount Diablo is the tall mountain that can be seen east of the Golden Gate Bridge behind San Francisco Bay and Oakland.

Mount Diablo is accessed via the Summit Road which is reached by the South Gate Road from the south and the North Gate Road from the north.  The South Gate Route is 10.5 miles from the state park entrance and averages a 5.8% grade on a 3,169 foot ascent.  The North Gate Road route is 12.4 miles long from the state park entrance and averages a 6% grade on a 3,687 foot ascent.  The vital statistics I just cited were obtained from Pjammey Cycling which is probably the best place to get grade information on notable Californian roadways.  The link below even has a handy map of both the South and North Gate Roads.

Pjammey Cycling on Mount Diablo

Given I just cited a cycling website you'd might imagine the road is popular for cyclists and you'd certainly be correct about that.  Signage warns drivers constantly to be leery of Cyclists.  My ascent to Mount Diablo was on the South Gate Road while my descent was on the North Gate Road.





The 1,000 foot line is reached quickly on the South Gate Road.





The South Gate Road has a ton of open vistas along sweeping cliff-side roadways that utilize numerous hairpins.


The actual gate on South Gate Road is actually several miles into Mount Diablo State Park.


Mount Diablo finally starts to come into view, the Summit Road really does go all the way to the top.





The South and North Gate Roads meet at the Walnut Creek Ranger Station which is about 2,000 feet above sea level.


The Summit Road is only 4.3 miles long but gains the bulk of the elevation up to Mount Diablo.  Apparently the average grade on the Summit Road is 6.7% but there is definitely a spot or two near the top over 10%.





The drive to the top of the Summit Road isn't fast with 15-20 MPH speed limits but it is plenty wide and well engineered.  I wasn't hurting for passing room for bikes or oncoming traffic on the ascent up to the summit.









The actual top of Summit Road is the actual 3,849 peak of Mount Diablo.


There is one hell of a view looking back south at all the switchbacks along Summit Road.  It reminds me of a miniature Pikes Peak Highway.






The views of the area were kind of obstructed eastward with a cloud hanging over the summit.






Part of Mount Diablo was acquired for State Park use in 1921 but it wasn't until 1931 that enough land was annexed before the park was formally dedicated.  The Summit Building was built sometime in the 1930s.





The drive back down to the Walnut Creek Ranger Station is stunning.  I used 1st gear most of the way down off the Summit Road given the speed limit was so low that I didn't feel a need to use my brakes up.












The North Gate Road is far less daunting than the South Gate Road.  There are a couple hairpins but they are far wider than the South Gate Road.  There was some minor road damage along the North Gate Road but nothing too out of control.  Unlike the South Gate Road the actual gate is at the state park boundary.











According to the Mount Diablo State Park brochure North Gate, South Gate, and Summit Road were all opened as stage routes in 1874.  Apparently the roads were closed sometime in the 1890s and reopened again by 1915.

Mount Diablo State Park Brochure

All three roads are clearly seen on the 1935 California Division of Highways map Contra Costa County as under county maintenance.

1935 Contra Costa County Map






 
Labels:

Comments

Post a Comment

Popular posts from this blog

Former US Route 50 and the Pioneer Route Lincoln Highway on Johnson's Pass Road

By
Johnson's Pass Road is one of the oldest highway corridors in California.  Johnson's Pass was part of the Lake Tahoe Wagon Road as it was completed during 1856 over the Sierra Nevada.  The pass would later be incorporated into the Pioneer Branch of the Lincoln Highway in 1913 and US Route 50 in 1926.  Johnson's Pass Road would be bypassed by a new alignment of US Route 50 over Echo Summit in 1938.  A replacement of the Meyers Grade east of Johnson's Pass would be opened to traffic in 1947.   Johnson's Pass Road remains accessible to traffic and is still signed by the Lincoln Highway Association.  Pictured as the blog cover is the view from the top of Johnson's Pass Road overlooking modern US Route 50 and Lake Tahoe.   Part 1; the history of Johnson's Pass Much of the history of what become the Lake Tahoe Wagon Road is discussed in the  September 1950 California Highways & Public Works  during its Centennial Edition.  The or...
Post a Comment
Read more

Former US Route 50 and the South Lincoln Highway from Folsom east to Placerville

By
The corridor of Folsom of Sacramento County east to Placerville of El Dorado County has been a long established corridor of overland travel dating back to the California Gold Rush.  The Folsom-Placerville corridor was once part of the path of the Lake Tahoe Wagon Road which became the first California State Highway and later the South Lincoln Highway.  In time the South Lincoln Highway's surface alignment was inherited by US Route 50.  The Folsom-Placerville corridor also includes the communities of; Clarksville, Shingle Springs and El Dorado. Part 1; the history of the Lake Tahoe Wagon Road, South Lincoln Highway and US Route 50 through Folsom-Placerville Folsom is located on the American River/Lake Natoma of eastern Sacramento County.  That lands now occupied by the City of Folsom were part of Rancho Rio de los Americanos prior to the finding of gold at Sutter's Mill during 1848.  During the California Gold Rush the lands of Rancho Rio de los Americanos were p...
Post a Comment
Read more

Old NC 10 - The Central Highway: Old Fort to Black Mountain through the Royal Gorge

By
A unique way of tracing the remnants of the Central Highway is through the mountainous terrain of Eastern Buncombe and Western McDowell Counties.  From the east on US 70, you reach the base of Blue Ridge Mountains at the town of Old Fort.  Old Fort is a tiny rail town that the old Central Highway and now US 70 goes through.  The Central Highway can be followed via a right onto Mill Creek Road from US 70.  Follow the highway as it takes you closer to the mountains.  When Mill Creek Road bears right to head towards Andrews Geyser stay straight until the road ends at a gate.  The nearby Piney Grove Church can be used for parking.  At this point, the old Central Highway began a 3.5 mile climb of the mountain to Swannanoa Gap.  NC 10 and later US 70 travelers followed this road for over 30 years until a new and modern four lane US 70 was built to the south.  This same four lane road would eventually become Interstate 40.    The Centra...
Post a Comment
Read more