Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
OMB APPROVAL
OMB Number: 3235-0287
Expires: January 31, 2005
Estimated average burden hours per response... 0.5

(Print or Type Responses)
1. Name and Address of Reporting Person *
Saathoff MardiLyn
  2. Issuer Name and Ticker or Trading Symbol
NORTHWEST NATURAL GAS CO [NWN]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
SVP, General Counsel & Reg.
(Last)
(First)
(Middle)
220 NW SECOND AVENUE
3. Date of Earliest Transaction (Month/Day/Year)
08/16/2018
(Street)

PORTLAND, OR 97209
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 08/16/2018   M   2,000 A $ 41.15 6,921.9572 (1) D  
Common Stock 08/16/2018   S   2,000 D $ 64.908 (2) 4,921.9572 (1) D  
Common Stock               1,160.149 I See Footnote (3)
Common Stock               7,637.677 (4) I See Footnote (5)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number. SEC 1474 (9-02)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Employee Stock Option to Buy $ 41.15 08/16/2018   M     2,000   (6) 03/04/2019 Common Stock 2,000 $ 0 (7) 0 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Saathoff MardiLyn
220 NW SECOND AVENUE
PORTLAND, OR 97209
      SVP, General Counsel & Reg.  

Signatures

 Shawn M. Filippi, Attorney-in-Fact   08/17/2018
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) Includes 1,549 of 3,100 restricted stock units (RSUs) granted under issuer's Long Term Incentive Plan. The 3,100 RSUs vest in three installments: 775 shares on each March 1, 2019 and 2020, and 1,550 shares on March 1, 2021. Pursuant to reporting person's previous election, only 50% of the shares received upon vesting of the RSUs, or an aggregate of 1,549 shares, will be directly issued to the reporting person, with the balance being credited to the reporting person's account under the issuer's Deferred Compensation Plan for Directors and Executives.
(2) This transaction was executed in multiple trades on reported date with prices ranging from $64.90 - $64.95, resulting in an average price of $64.9080. Northwest Natural Gas Company ("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 price.
(3) Shares held in reporting person's account under Issuer's Retirement K Savings Plan as of July 31, 2018.
(4) Includes 1,551 of 3,100 RSUs granted under issuer's Long Term Incentive Plan. The 3,100 RSUs vest in three installments: 775 shares on each March 1, 2019 and 2020, and 1,550 shares on March 1, 2021. Reporting person has previously elected that 50% of shares received on vesting of RSUs, or an aggregate of 1,551 shares, will be deferred under the issuer's Deferred Compensation Plan for Directors and Executives.
(5) Shares have been credited to reporting person's account under the Issuer's Deferred Compensation Plan for Directors and Executives.
(6) The option vested in four equal installments on February 25, 2010, and January 1, 2011, 2012 and 2013.
(7) Option was granted as part of compensation for services. The option was exercised as a cashless exercise.

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB number.