Cycling Mt. Diablo - An East Bay Jewel
Mt. Diablo is a very popular East Bay State Park that offers many hiking trails, camping options, and excellent views of the Bay Area and east towards the Sierra Nevada Mountain Range. It is no coincidence that Diablo is “Devil” in Spanish, an appropriate name for this lengthy and challenging East Bay bike climb.
There are 360 degree views from the visitor center and observation deck at the mountain’s summit.
There is a historic beacon tower and museum-like visitor center at this bicycle climb’s finish. “Mount Diablo is the starting point for the establishment of land boundaries throughout most of Northern California and all of Nevada. The summit is the location of the "Initial Point," the north/south meridian, and east/west baseline intersection point that is the basis for most property boundaries” (see history article).
Mt. Diablo Visitor Center at the Mountain's Summit:
Summit sign, Visitor Center Parking Lot and Beacon.
Standard Oil Beacon -- activated 1928; now lit once a year on December 7.
The observation deck and beacon tower.
Inside the Beacon Tower.
Inside the Visitor Center.
Junction of South and North Gate Roads
There is water at the Junction Ranger Station (mile 6.1 from the south, and 7.9 from the north) and at Summit.
Junction Ranger Station.
Water at Junction Ranger Station.
The Visitor Center at the summit has candy, liquids and four options of cycling jerseys to purchase (that is notable in that it’s the largest selection of jerseys in any visitor center we’ve visited in the US, most don’t have even one to choose from).
Both the South and North Gate climbs are broken into two segments:
Summit Road leading to Visitor Center and Beacon (view west)
Winding road after the merge of South/North Gate Roads.
Northeast view of Shiloh Wind Power Plant -- Birds Landing.
Mt. Diablo From South Gate:
We begin this climb 0.3 miles outside the park entrance (South Gate Road) in the community of Diablo, just east of Danville, CA. The climb starts at the end of a rural residential area and for the remainder of the 10 1/2 miles we travel through a very rural oak studded open space California State Park.
Start of South Gate climb.
On a crystal clear day, it is reported that one can see the Sentinel Dome in Yosemite (130 miles due east), Mt. Lassen (170 miles north) and the Farallon Islands (60 miles due west) west of the Golden Gate Bridge. For most of the climb, our view is of grasslands with many interspersed valley, blue, and black oak tree varieties. The Climb averages 5.8% and is a very smooth and comfortable ascent (in the 4-7% range, for the most part) save for the last two-tenths mile (“The Wall” -- Strava has it at 0.1 mile, but we charted it closer to 0.2) which averages 15%. Views along the route are to the west and north of the Walnut Creek and San Pablo Bay areas and to the east of the Highway 4 corridor (Pittsburg / Antioch / Brentwood areas) all the way to the western Sierras.
Golden Gate Bridge center top
Mt. Tamalpais is the bump on the mountain range upper center-right.
Exceptional views from the summit.
If you are driving from out of the area and just doing the climb, parking is difficult in the park and within a 1-2 mile perimeter outside of it in the bordering residential areas. We recommend parking at Rock City Live Oak Camping and Parking area just past the ranger kiosk at mile 3.9 ($10 parking and day use fee -- no charge for cyclists as of May 2015).
The roadway surface is exceptional and while there is moderate vehicular traffic along the climb, our experience in three times up Diablo is that traffic travels at or near the posted 20 mph speed limit, making this a very safe route. You will also likely encounter many cyclists along the climb. Be sure to turn right onto Summit Road at the North and South Gate junction (mile 6).
Mt. Diablo From North Gate:
This segment is a bit more difficult to Summit Road than South Gate (7.9 versus 6.1 miles, and 5.4% versus 4.5%) and a bit more exposed with less shade, so beware and come prepared on hot days. As for popularity, South Gate to Junction had 71,790 Strava attempts as of September 1, 2015 versus only 36,589 for the equivalent segment from the north.
Start of climb -- North Gate Road and Castle Rock Road.
Enter park at mile 1.4.
North Gate Road from Walnut Creek.
As with the southern approach, the road along the entire ascent from the north is exceptional. Traffic can be heavy on the weekends, but there are so many cyclists and the speed limit so low, this is a very safe climb.
TOUR OF CALIFORNIA
Leopold Konig wins Stage 7 of the 2013 mountain-top finish Mt. Diablo (Jonathan Devich).
Mt. Diablo has been featured three times in the Tour of California between 2006 and 2019.
Peter Sagan wins ToC 2012 Stage 3.
Rohan Dennis wins ToC 2014 Stage 3 mountain-top finish on Mt. Diablo.
Photo: AP Marcio Jose Sanchez