X0306 4 2017-09-26 0 0000073020 NORTHWEST NATURAL GAS CO NWN 0001292529 Byorum Martha L 220 NW SECOND AVENUE PORTLAND OR 97209 1 0 0 0 Common Stock 2017-09-26 4 J 0 1202 0 D 0 I See Footnote Common Stock 2017-09-26 4 J 0 1202 0 A 1202.047 D Common Stock 2017-09-27 4 S 0 1202.047 64.8831 D 0 D Common Stock 8693.64 I See Footnote Shares were distributed from Directors Deferred Compensation Plan (DDCP) account to reporting person's registered account pursuant to reporting person's election on September 19, 2017 for an accelerated distribution of a lump sum equal to ninety percent of the total share balance of reporting person's DDCP stock account as of June 30, 2017. Ten percent of the total share balance of reporting person's DDCP stock account as of June 30, 2017, representing 134 shares, was forfeited pursuant to the Accelerated Distribution provisions of the DDCP of Northwest Natural Gas Company (Issuer). Shares credited to reporting person's account under the Issuer's DDCP. This transaction was executed in multiple trades on reported date with prices ranging from $64.75 to 65.05, resulting in an average price of $64.8831. Issuer will provide upon request by the Commission staff or a security holder of the Issuer full information regarding the number of shares purchased or sold at each separate transaction. Includes 328 restricted stock units (RSUs) granted in accordance with the Northwest Natural Gas Company Compensation Policy for Non-employee Directors. These RSUs vest on May 23, 2018. Director previously elected that shares received on vesting of RSUs will be deferred under the Issuer's Deferred Compensation Plan for Directors and Executives (DCP). Shares have been credited to reporting person's account under the Issuer's DCP. Shawn M. Filippi, Attorney-in-Fact 2017-09-28