X0306 4 2015-03-04 0 0000073020 NORTHWEST NATURAL GAS CO NWN 0001192779 KANTOR GREGG S 220 NW SECOND AVE PORTLAND OR 97209 1 1 0 0 President & CEO Common Stock 2015-03-04 4 F 0 1200 46.57 D 38699.0574 D Common Stock 2015-03-04 4 F 0 730 46.57 D 37969.0574 D Common Stock 2015-03-05 4 M 0 3000 34.29 A 40969.0574 D Common Stock 2015-03-05 4 S 0 2524 45.8558 D 38445.0574 D Common Stock 5633.848 I See Footnote Common Stock 3920.3020 I See Footnote Common Stock 200 I See Footnote Common Stock 570 I See Footnote Employee Stock Option to Buy 34.29 2015-03-05 4 M 0 3000 0 D 2010-01-01 2016-02-29 Common Stock 3000 0 D 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 were withheld by the issuer to cover withholding taxes on issuance of performance shares. Organization and Executive Compensation Committee certification of the payout of these performance shares was reported on Form 4 filed on February 27, 2015. Reporting person exercised an option to purchase 3,000 shares at $34.29 each and then sold 2,524 of those shares at prices ranging from $45.84 to $45.86, resulting in an average price of $45.8558 on March 5, 2015 to generate the proceeds required to purchase the remaining 476 shares of the Company common stock under the option. Shares have been credited to reporting person's account under the issuer's Deferred Compensation Plan for Directors and Executives. Shares held in reporting person's account under issuer's Retirement K Savings Plan as of February 28, 2015. Shares held in reporting person's parent's account, with respect to which the reporting person is Power of Attorney and a potential beneficiary. Shares held in reporting person's parent's IRA account, with respect to which the reporting person is Power of Attorney and a potential beneficiary. The option representing the right to purchase 3000 shares became exercisable in four equal installments beginning February 22, 2007, and ending January 1, 2010. Shawn M. Filippi, Attorney-in-Fact 2015-03-06