Here's one out of Sonoma Valley
http://jacklondonpark.com/jack-london-trail-bay-area-ridge.htmlDistance, category, and difficulty:
This 7 mile out and back hike is moderate, with about 1500 feet in elevation change. Park elevation ranges from about 400 to nearly 2400 feet. The featured hike starts at the Beauty Ranch parking lot, at about 700 feet and climbs to 2100 feet, then descends back to the trailhead. Elevation changes are mostly gentle, with numerous switchbacks, but this is a long hike.