Regional ESZ boundaries

Regional ESZ boundaries as of June 2025 The Emergency Service Zone (ESZ) layer is derived from the union of all discipline-specific Emergency Service Boundary (ESB) layers — ESB_LAW, ESB_FIRE, and ESB_EMS. Each ESZ represents a unique combination of responding law enforcement, fire, and EMS agencies for a given area and is assigned a unique Emergency Service Number (ESN) used for 9-1-1 call routing.