Altamont Pass-Patterson Pass-Collier Canyon

Sunday, November 6, 2016

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Today’s route heads east towards Livermore Valley on Highland Rd to N Livermore Ave. It goes up Altamont Pass through the windmill farms to Grant Line and crosses I-580 on Midway Rd. It continues along east Patterson Pass Rd for the beautiful remote climb to the summit. The route drops back down into Livermore Valley and returns west via Portola Ave and Collier Canyon Rd.

Exit the parking lot onto Camino Tassajara; this road heads south out of town towards the backcountry with wide-open pastoral ranch lands and rolling hills through the unincorporated town of Tassajara.

Highland Rd travels east on rolling terrain through “horse country” with boarding ranches and equestrian facilities. The beautiful hills are dotted with grazing cattle and scattered barns.

The short climb up on Highland has gradient ranges of 3-6%; it takes you out along the valley farms and ranches on false flat terrain before dropping into Alameda County onto Manning Rd.

Roll through the flat lands on Manning Rd to N Livermore Ave.

Side step through the open scenic Livermore Valley on May School, Dagnino and Raymond Ave to the edge of the Springtown neighborhood in Livermore.

Broadmoor and Scenic Ave cuts through the neighborhoods to Herman Rd; this leads you onto Northfront Rd which runs alongside I-580.

The road name changes to Altamont Pass Rd and continues east past Greenville Rd and the Club Moto Motorcross track.

Altamont Pass Rd goes under the train trestle and ascends with minimal traffic on rolling terrain with gentle gradient ranges of 2-3.5% for the next 3.2 miles to the top at the Summit Garage.

The rolling descent on Altamont Pass Rd to Grant Line Rd is quite scenic and fun; windmills dot the landscape as you pass through the Altamont Pass Wind Farms along the Diablo Range.

Head south on Midway Rd along the California Aqueduct and cross under I-580 through a small ranching community.

The road climbs up with 4-7% grades towards the closed Altamont Speedway before dropping down into the valley to the Altamont Pass Wind Farm Substation.

Patterson Pass Rd is a quiet less-traveled remote back road; from Midway Rd, it stretches east to west along the Diablo Range for 11.5 miles into Livermore.

The climb begins as you round the substation to Mulqueeney Ranch; it’s 3.1 miles with an average grade of 4.8% up to the Patterson Pass Windfarm.

From the windfarm, the road kicks up with steep grades of 9-11% for 3/10th of a mile as it winds around the hill and levels out at the false summit.

Look ahead and you can see the infamous section of this road leading up to Patterson Pass; aka “Oh-My Gosh” summit on the course of Devil Mountain Double.

It’s really not as bad as it looks; the road dramatically tilts up and stair-steps for the next 0.8 mile with an average grade of 7%.

The last 0.2 mile up to the summit is the steepest section with 12-16% grades!

Enjoy the stunning valley views from the summit and check out the road that got you there-WOW!

Patterson Pass Rd quickly descends along the back side of the ridge to Cross Rd and continues winding down the valley into Livermore.

Stay on Patterson Pass Rd past the Lawrence Livermore National Laboratory and Industrial Business Park area to Vasco Rd. The road enters a residential neighborhood before coming to a T at N Mines Rd.

The right turn on Mines Rd takes you across an overpass to First St. Continue east on First St and make your way through Livermore on Portola Ave. The road leads you out of town and over I-580 to the newer subdivisions around Las Positas College and Collier Canyon Rd.

Collier Canyon Rd is another quiet less-traveled road; it stretches 5.5 miles on gentle rolling terrain from the south end in Alameda County to the north end at Highland Rd in Contra Costa County. This back road takes you through a horse and cattle ranching community.

Grazing cattle and horses dot the landscape along with old farm equipment and weathered wooden barns.

The canyon has several horse boarding facilities with large paddocks and pastoral lands.

At the intersection with Carneal Rd, Collier Canyon climbs gently for about a mile with grades of 2-4.5% up to the old water tower and windmill. The fast descent drops down onto Highland Rd.

At Highland Rd, reverse your way out to Camino Tassajara.

Take Camino Tassajara back to the suburban neighborhoods around Blackhawk.

This wonderful ride heads out from the suburbs in Danville to Livermore Valley and through the remote less-traveled back roads and windfarms along the Diablo Range. The climb up to Patterson Pass is not a give-me but you’ll be greatly rewarded with the spectacular valley views and summit vistas! The windmills are out there for a reason; it’s a good idea to check wind conditions prior to planning the ride.

Garmin Stats:
54 Miles with 2713′ of elevation gain
Max elevation: 1587′
Max grade: 16%
Terrain: Flat-rolling with steep climbs on Patterson Pass Rd

Weather: Cloudy skies with cool temps ranging from the high 50’s to the high 60’s with SW winds.

View the interactive RGPS route map & profile


Follow this route for today’s ride:


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