Bald Mountain Bike Climb - PJAMM Cycling

4.1 mi
2,047 ft
9.5 %



Bald Mountain is the most difficult bike climb in Sonoma County. In our opinion this is the best climb, and the only mountain top 360 degree views in the county.  
This climb is a beast from start to finish.  The average grade is 9.5%.  33% (1.4 miles) of the climb is at 5-10%, another 33% is 10-15%, and 16% (0.6 miles) is in the daunting 15-20% range.  The steepest quarter-mile is 16.4% and there is a continuous half-mile that averages 14.2%. 

See more details and tools regarding this climb's grade via the “Profile Tool” button.
Roadway:  The first 1.1 miles are on a quiet state park paved road in excellent condition.  The next 2.5 miles are on a short stretch of dirt, and then after passing a gate on a broken and narrow single lane road.  The final 4/10ths of the climb are on dirt with grades of 20% that are nearly impossible to ride on road bike tires - in my younger days I could make it on 25mm but now ride my Roubaix with 32mm knobby tires. 

Traffic:  Minimal for the first 1.1 miles and none for the final 2.9.

Parking:  There is a parking lot (with state park fee - honor system) at the start of the climb - MapStreet View
There are beverages and snacks just past the entrance kiosk on the right at mile 1.1.
Before heading out on any cycling adventure check out our Things to Bring on a Cycling Trip and use our interactive check list to ensure you don't forget anything.
There is certainly no shortage of hotel options in the Kenwood area, located right in the heart of wine country in gorgeous Sonoma County.  Additionally, the area has tons of options for unique and beautiful vacation rental homes.

If you have travelled to Sonoma County to cycle or have any questions concerning cycling in the North Bay, you are welcome to contact me at with your questions about the area - I grew up and live in Sonoma and have good knowledge of cycling in this region.



Difficulty: Extreme



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Sep 29, 2021
difficulty: Extreme
scenery: 4
traffic: 5
road: 2
Sep 29, 2021
scenery: 4
traffic: 5
road: 2
A tough climb that needs respect from the start as it get gradually harder the higher you go. Great view from the summit. The right gears and tire choice are crucial if you don’t like hiking ;-)

Climb Profile Not Found

Sunrise atop Bald Mountain January 1, 2015.

Climb summary by PJAMM’s John Johnson.

Bike climb up bald mountain - map at the top with mountains 

Cycling Bald Mountain - very challenging - 33 mm tires recommended.

Ride 4.1 miles to 2,733’ gaining 2,122’ at 9.5% average grade.

Steepest ¼ mile is near the top - 17%

cycling bald mountain Sonoma County; cyclist at top; bicycle;

This climb ranks as the #2 most difficult on the Tri-County Top Climbs list with  an  eye  popping (for these parts) FIETS Index of  6.15 (this is only 1 of 2  climbs in the tri-  county area that top 6 on the FIETS scale). Located in the  Mayacamas Mountain  range, Bald Mountain is, for a number of reasons, a  very challenging ascent, but with  360 degree views from the top  unparalleled in Sonoma/Napa/Lake counties.  

Climb Bald Mountain by bike - bicycle leaning against map at top with mountains in background

95% of the route is located in Sugarloaf State Park (4,020 acres) which is in the Mayacamas Mountains. Bald Mountain is the high point of the park and we climb to the top on this bike ride.  The Bald Mountain is situated between the lush Sonoma and Napa valleys and both are visible from the climb’s finish.  Bald Mountain and Mt. St. Helena (Napa/Sonoma) are the only points in Wine Country where you have 360 degree views of Sonoma and Napa vineyards.

 From its peak at 2,673' (by our Garmin - the official elevation is 2,729')  we have  spectacular and unobstructed views of the Sonoma Valley to the west, San Pablo  Bay/Mt Tamalpais to the south, Mt. Diablo to the southeast, Napa County to the  east,  and Mt. St. Helena to the north.

   Traffic/Roadway surface:  O.k. - here's the rub.  The first mile is on a well  maintained and good state park road.

Bike climb to Bald Mountain - road and forest - start of climb

 At the 1.17 mile mark, ​we turn left ​onto gravel  for .5 miles at 5.8% (manageable, even on a road bike).

Turn left at the ranger kiosk at mile 1.1

Climb Bald Mountain by bike - sign and gravel section

The  next 1.9 miles are on  very rough, broken and rutted pavement with  much gravel and debris (very, very  hazardous on the descent) at 10.6%.

Climbing Bald Mountain by bike - gate at end of gravel section

Gate at mile 1.5

 And, that's not the worst part - at mile 3.57 we  encounter gravel for the remainder of the climb at 11.3% average grade (the first .1 at 21%).  ​

Cycling Bald Mountain - steep gravel section near the top

The Wall




Gettin there!!

Napa Valley to the east

 Mt. Tamalpais to the south

Mt. St. Helena north - center background of photo.

On our attempts via road bike (3 times up on cross bike - no problem), we did make it to the top once without dismounting, but this ride  is much better  suited to the cross or road bike.  The  descent, in our opinion, is the most difficult in Sonoma County.  The positive side, other than the occasional  hiker, or nutty  cyclist, no traffic as the road is closed  to all but official vehicles.

When I was only 55 I climbed this baby with 28mm tires + 34 chainring + 27 cassette.

May, 2019 at 62 = 33mm knobby’s + 34 chaingring + 42 Cassette . . . NO PROBLEM!  👍😊

That’s a wrap!

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