Sonoma Mountain Road West Bike Climb - PJAMM Cycling

Sonoma Mountain Road West


Short, rough, steep climb near Petaluma.

Explore this Climb

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Climb Summary

Cycling Sonoma Mountain Road West

Ride 5.2 miles gaining 1,950’ at 6.8% average grade.

Sonoma Mountain Road West is the eighth most difficult bike climb in Sonoma County, with a Fiets Index of 3.8. The climb passes through classic Sonoma County pastureland (yes, not vineyard!) and is fairly remote, with minimal traffic.  

Through the middle portion of the ride (~ miles 3-4), there are very scenic views west towards Old Adobe Road, the historic farming town of Petaluma, Mt. Tamalpais 25 miles south, and Mt. St. Helena 25 miles north.  

Beautiful (and rustic) Sonoma County farmland.

This is a scenic ride where we are surrounded the entire trip by rolling hills, fields, and distant views of open space.  Toward the top of the mountain climb, riders can expect to see 180-degree views stretching from Santa Rosa all the way to the San Pablo Bay.  On an clear day, it’s possible to see as far south as the rust-colored arches of the Golden Gate Bridge.  The climb has some severe grades along two 50 yard segments.  It also has four segments of 100 to 400 yards that average over 16% (the steepest quarter mile on the climb averages 17.6%).


Traffic and Roadway Surface Report:  There is very little traffic along this very narrow roadway (wide single-lane, or narrow two-lane).  The roadway surface is extremely poor and there is quite a bit of loose gravel, as well as deep potholes, which justify using extreme caution on the descent.  Though the gorgeous views may tempt you, it is advisable to keep your eyes on the road during the descent so you can avoid any potentially dangerous rough patches of pavement.

Rough road and all, this is one fantastic bike ride.

That’s a wrap!