Cell phone service is limited in Big Sur. For a rough approximation of where cell service is available along Highway 1, visit RootMetrics, enter 93920 in the Search field. Do NOT assume that you’ll experience the same coverage. Ask someone who lives or works in Big Sur, they may be able to direct you to nearby locations with cell service. Many businesses, parks and camp grounds have pay phones available, should you be unable to find an area with cell service.
Cell network strength can vary by topology, time of day, weather, and whether you’re located inside or outside of a vehicle or building. Also, cell networks periodically go off-line in Big Sur. To date, it’s not been economically and environmentally feasible to install sufficient network towers to provide cell coverage through all of Big Sur.