On Eastside Road in Potter Valley between Pine Avenue and Mid-Mountain Road. Just north of milemarker 4.77 there is a vineyard pond behind an elevated berm on the west side of the road. The Tricolored Blackbird colony is in the Himalayan Blackberries which extend the full length of the pond on its south side.
Directions: From Highway 20 about 3.5 miles east of Highway 101 turn north onto Potter Valley Road. In 2.25 miles Potter Valley Road becomes Eastside Road. Continue straight ahead for about 2.5 miles to milemarker 4.77. The pond is just ahead on the left. The only place to park is in a small mailbox pullout on the left shoulder, Number 10707. The east end of the colony can be observed from here.
You can see a Google Earth sattelite image in the gallery.