About NW Natural Holdings Northwest Natural Holding Company (NYSE: NWN) (NW Natural Holdings) is headquartered in Portland, Oregon and has been doing business for over 167 years. It owns Northwest Natural Gas Company (NW Natural), SiEnergy Operating (SiEnergy Gas Utility), NW Natural Water Company (NWN Water Utility), NW Natural Renewables Holdings (NWN Renewables), and other business interests. NW Natural Holdings through its subsidiaries provides critical energy and delivers essential water and wastewater ...