Pine Flat Road Bike Climb - PJAMM Cycling

4.4
FIETS
11.2 mi
DISTANCE
3,149 ft
GAINED
4.9 %
AVG. GRADE

FULL CLIMB STATS

Photos By: Maxfield Bonta

INTRO

Cycling Pine Flat Road: One of the most challenging and popular bike climbs in Sonoma County's Wine Country.  Sadly, the area has been decimated by fire although there is nice greenery and wildflowers during the spring. 
There are several flat to descent segment on this climb, most notably the 2.2 miles at -0.7% past the guardrail beginning at mile 6.8. Many cyclists stop at the guardrail and rightly so - the 2.2 mile flat is followed by 1.4 miles at 11%, culminating at "The Wall," which is an approximate half-mile segment beginning just before mile ten that averages 15%.  The steepest quarter-mile of the climb is 16.2% and there is a continuous mile averaging 12.1% that includes the Wall segment at the top.  Eliminating descent from the gradient calculation raises the average grade of Pine Flat to 6.8% and 13% of the climb is ≥10% grade.
 
See more details and tools regarding this climb's grade via the “Profile Tool” button.
Roadway:  The roadway is good until the last couple of miles which are rough, have debris, and must be descended with caution.

Traffic:  Negligible.

Parking:  Along  the vineyards on the right side of the road on Pine Flat Road about 50-100 yards from the start.  Map; Street View.
Provisions:  There is no water or food on this route and it can get very hot during the summer - bring plenty of water.  The closest provisions are in Geyserville eight miles northwest (Map), or Healdsburg seven miles southwest (Map).  The Jimtown Store is a mile west of the climb on Highway 128 and may be an option if it has reopened after its closing in 2020 (Map).
This is primarily a locals climb, but if you are in Sonoma County to cycle, be sure to consider Pine Flat as one of your climbing options. Use the “Routes in Area” button on the menu bar above to see other bike climbs in this area. 

f 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 John@pjammcycling.com with your questions about the area - I grew up and live in Sonoma and have good knowledge of cycling in this region.

ROUTE MAP

MEMBER RATING

Difficulty: Challenging
3
Road
5
Traffic
4
Scenery

CURRENT WEATHER

NEARBY CLIMBS (0) RADIAL PROXIMITY

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Apr 13, 2021
difficulty: Challenging
scenery: 4
traffic: 5
road: 3
Apr 13, 2021
scenery: 4
traffic: 5
road: 3
First 4-5 miles you wonder if you are actually on a climb. Then the grade starts to pick up a bit with some steeper grades. Beware of 5 cattle guards along these segments. Then you reach a flattish portion of about two miles before hitting the wall. There is a pre-wall (maybe 12-14%) where you are thinking this wall isn’t so bad. Then it flattens out and you hit the real wall. Plenty of wide open beautiful views to try and enjoy while you suffer up the wall and attempt to avoid the slippery gravel spots or looking at the grade on your computer! Overall an enjoyable climb with one steep (longish segment) at the top.
ROUTE MAP
PROFILE TOOL

Climb Profile Not Found
CLIMB SUMMARY

Climbing Pine Flat Road by bike - aerial drone photo of roadway, hillside, mountains and vineyards.

Cycling Pine Flat Road -- Sonoma County’s fourth most difficult bike climb.

Ride 11.2 miles to 3,158’ gaining 3,589’ at 4.9% average grade.

Bike ride up Pine Flat Road - aerial drone photo of start and vineyards 

Looking back from the start via drone aerial photo.

Pine Flat is located in the Mayacamas Mountains, which stretch 52 miles from Clear Lake in Lake County, to northern Sonoma and Napa counties.

Climbing Pine Flat Road by bike - cyclist on road

First stretch of Pine Flat Road.

Lower portion of the climb.

Biking up Pine Flat Road - cyclist on the wall, roadway

Aerial drone panorama of mile three to finish.

The first seven miles of Pine Flat (to “the guardrail” as the locals refer to it) are a modest ascent at 5.5% average grade, followed by 2.1 miles that actually averages -0.8% grade (perhaps where the "flat" part of the road's name comes from).

Mile 3.5.

“The Guardrail”

Spot on mile seven.

Two Pine “Flat” miles after the guardrail.

The biggest challenge of this climb comes toward the end, with the last 2.2 miles averaging 9.2%, with 1.1 mile at the beginning of that stretch averaging 11.4% (20% for a brief time on "The Wall" at the 10.1 mile mark.) The upper portion of the ride approaches The Geysers area and can be torturously hot in the summer.  

Read it and weep -- the Garmin don’t lie!

Peak gradient on “The Wall”.

“The Wall” -- ¼ mile at 16% beginning at mile 10.2.

Bicycle climb of Pine Flat Road - cyclist on the roadway on bikes with road and power lines

Section just after The Wall.

Pine Flat in spring.


Roadway Surface and Traffic Report:  The roadway is in decent condition at the bottom, with moderate deterioration towards the top.  Caution is required for the decent, as the upper portion of the mountain is very steep with rough road, sharp turns and  gravel in many locations.  Traffic over the entire climb is minimal.

A LITTLE HISTORY

Old structure at the start of the climb.

There were hundreds of mercury (“quicksilver”) permits drawn in the 1870s, and many active mines operating in Sonoma County in the late 19th and early 20th centuries.  The last mine to close was the Mount Jackson Mercury Mine, located in the Sonoma County town of Guerneville on Sweetwater Springs Road, which operated from 1889 to 1972.  The largest mining town was Pine Flat, which grew up around the mercury mine in that area. (Santa Rosa Press Democrat, July 11, 2010 “The Lasting Impact of Mercury”) and in its hay day consisted of 60 homes, three hotels, two dry goods stores, a fruit vendor, bakery, lumber yard, two shoe shops, two laundries and six saloons -- no churches or schools, however! The structure pictured above may be related to the Pine Flat mining town, although the original town was located three to four miles up Pine Flat Road, and there are no obvious signs of the town remaining.

Photos in this section are from the Pressdemocrat’s article titled Boomtown’s Bust,

written by Clark Mason and published December 11, 2014.

Photo courtesy of Healdsburg Museum.

In the 1870s, Pine Flat may have been the fastest growing town in Northern California, born of the mercury boom during that time.  Pine Flat’s population in the 1870s is estimated at 1,000-4,000.  Seventy claims were filed in this area, known as Cinnabar Mining District, with colorful names such as Fandango, Mohawk, Socrates, and Rattlesnake.  The Press Democrat’s article Boomtown’s Bust, by Clark Mason, is quite entertaining and a good read for those interested in Sonoma County History.

That’s a wrap!!