Del Puerto Canyon Rd starts east of Patterson near Hwy 5 exit. For about 30 km, you wind your way up through the canyon gaining about 300 m - that's only a 1% grade.
As the canyon narrows, you hit a 12% wall. As you approach the top on this 3.5 kilometers climb it getting easier (about 7%-8%). From the pass you roll down to Junction Cafe.
From the Junction, you can continue North to Livermore via Mines Rd. Alternatively, you could go South / East climbing the back road to Mt Hamilton.
Del Puerto Canyon Rd is also subject of the Early Bird Road Race, organized by Velo Promo. Start is in Patterson. You climb up, go a kilometer beyond the pass and turn around.