X0306 4 2015-03-04 0 0000073020 NORTHWEST NATURAL GAS CO NWN 0001629792 Filippi Shawn M 220 NW SECOND AVE PORTLAND OR 97209 0 1 0 0 VP & Corporate Secretary Common Stock 2015-03-04 4 F 0 41 46.57 D 389.6829 D Common Stock 605.9607 I See Footnote Shares were withheld by the issuer to cover withholding taxes on issuance of shares due to vesting of restricted stock units. Organization and Executive Compensation Committee certification of satisfaction of the performance threshold and vesting for these restricted stock units was reported on Form 4 filed on February 27, 2015. Shares held in reporting person's account in issuer's Retirement K Savings Plan as of February 28, 2015. Shawn M. Filippi 2015-03-06