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 *
HOLBROOK CONNIE C
  2. Issuer Name and Ticker or Trading Symbol
QUESTAR CORP [STR]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
_____ Officer (give title below) __X__ Other (specify below)
Retired Senior Vice President
(Last)
(First)
(Middle)
180 EAST 100 SOUTH
3. Date of Earliest Transaction (Month/Day/Year)
09/09/2005
(Street)

SALT LAKE CITY, UT 84111
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 and attached Common Stock Purchase Rights 09/09/2005   M   1,717 A $ 22.95 191,988 D  
Common Stock and attached Common Stock Purchase Rights 09/09/2005   F   1,015 D $ 81.23 190,738 (1) D  

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
Common Stock and attached Common Stock Purchase Rights $ 22.95 09/09/2005   M     1,717 08/11/2002 02/11/2012 Common Stock and attached Common Stock Purchase Rights 1,717 $ 22.95 89,940 D  
Phantom Stock Units $ 0               (2)   (2) Phantom Stock Units 0   8,491.4229 (3) D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
HOLBROOK CONNIE C
180 EAST 100 SOUTH
SALT LAKE CITY, UT 84111
      Retired Senior Vice President

Signatures

 Abigail L. Jones Attorney in Fact for C. C. Holbrook   09/12/2005
**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) I exercised an option to purchase 1,717 shares of stock using 485 shares as consideration. I satisfied my tax withholding obligation by selling 530 shares to Questar. This total also reflects a gift of Stock for 235 shares made on a voluntary disclosure basis on September 8, 2005.
(2) Phantom stock units will be converted to cash beginning one year after my retirement. I retired effective April 30, 2005.
(3) During my employment, I also received phantom stock units as a result of my participation in an excess benefit plan. This total includes 3,592.1336 units in such plan in addition to units held through my account balance in a deferred compensation plan. I receive dividends on those units.

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.