Sec Form 4 Filing - RATTIE KEITH O @ QUESTAR CORP - 2012-10-15

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 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

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1. Name and Address of Reporting Person RATTIE KEITH O 2. Issuer Name and Ticker or Trading Symbol QUESTAR CORP [ STR] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 333 SOUTH STATE STREET 3. Date of Earliest Transaction (MM/DD/YY) 10/15/2012 (Street) SALT LAKE CITY, UT84145-0433 4. If Amendment, Date Original Filed (MM/DD/YY) 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 (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 10/15/2012 M 100,000 A $ 12.43 479,821 D Common Stock 10/15/2012 F 77,004 D $ 20.47 402,817 D Common Stock 10/16/2012 M 25,000 A $ 4.365 427,817 D Common Stock 10/16/2012 S 25,000 D $ 20.5 402,817 ( 1 ) D Common Stock 10/17/2012 M 25,000 A $ 4.365 427,817 D Common Stock 10/17/2012 S 25,000 D $ 20.514 402,817 ( 1 ) D Common Stock 2,646 I IRA Common Stock 10,000 I The Rattie Family Foundation

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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 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 Stock Option $ 12.43 10/15/2012 M 100,000 06/30/2010 10/24/2012 Common Stock 100,000 $ 12.43 0 D Stock Option $ 4.365 10/16/2012 M 25,000 08/11/2003 02/11/2013 Common Stock 25,000 $ 4.365 75,000 D Stock Option $ 4.365 10/17/2012 M 25,000 08/11/2003 02/11/2013 Common Stock 25,000 $ 4.365 50,000 D Restricted Stock Unit $ 0 ( 2 ) ( 2 ) Common Stock 70,824.212 70,824.212 D Stock Option $ 11.4 06/30/2010 03/05/2016 Common Stock 147,174 147,174 D Stock Option $ 13.235 06/30/2010 02/13/2015 Common Stock 80,000 80,000 D Stock Option $ 17.35 06/30/2010 02/12/2016 Common Stock 30,000 30,000 D Stock Option $ 13.1 06/30/2010 03/05/2017 Common Stock 125,000 125,000 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other RATTIE KEITH O 333 SOUTH STATE STREET SALT LAKE CITY, UT84145-0433 X Signatures Julie A. Wray, Attorney in Fact 10/17/2012 Signature of Reporting Person Date

Explanation of Responses:

( 1 )These shares sold were disclosed by my Form 144 filed on 10/16/2012 and 10/17/2012 pursuant to a Rule 10b5-1 plan entered into on 9/10/2012. ( 2 )The restricted stock units vest in three equal annual installments beginning on July 1, 2011, subject to accelerated vesting upon the occurrence of certain events a set forth in the award agreement.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

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