I live in Northern CA too, about 40 miles Easy of Sacramento. I live in Comcast's zone (so I get 100/5) but my friend .5 mile away only has DSL as an option. A lot of people around me have to use radio frequency internet or satellite. Before I even considered a house, I would first confirm with Comcast that they serviced that house. Double check though! We were in escrow for a different house before I realized Comcast had given me the wrong info the first time.