Did you receive a census form? If you live in Montara, Moss Beach or El Granada your form might have been lost in a bureaucratic Catch-22. As Margot Grant, the San Mateo County Census Coordinator explains in this video, the Census Bureau will only mail to physical addresses, our post offices will only accept mail to P.O. Boxes.
It is not clear how much of an affect this problem is having–the areas with PO boxes have a 67% return rate versus a 70% rate county-wide.
Look for Census forms in a brochure stand at your local post office if you want to be counted.