Take 101 north, go past the Petaluma exits until the last one which says Petaluma Blvd. North and Pengrove (Old Redwood Hwy) go north on Old Redwood Hwy by bearing to your right and turn right after you exit 101. Go a mile. You will pass Pengrove, stay on Redwood Hwy. Go another two miles toward Cotati. On your right (it only goes right) is a street called Fern. Turn right there go to the end of Fern Ave. aprox. 1/2 mile. You will be looking at a long gravel driveway directly in front of you at the end of Fern (Fern dead ends into Willow Ave) go directly accross the street down the long gravel driveway (9540 Willow Ave,) You will be there.