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

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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) 05/25/2005 (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 05/25/2005   M   43 A $ 21.375 152,263 D   Common Stock and attached Common Stock Purchase Rights 05/25/2005   M   3,570 A $ 28.01 155,833 D   Common Stock and attached Common Stock Purchase Rights 05/25/2005   F   1,671 D $ 59.75 184,471 (1) D

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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

$ 21.375

05/25/2005

M

43

08/10/1998

02/10/2008

Common Stock and attached Common Stock Purchase Rights

43

$ 21.375

113,900

D

Common Stock and attached Common Stock Purchase Rights

$ 28.01

05/25/2005

M

3,570

08/13/2001

02/13/2011

Common Stock and attached Common Stock Purchase Rights

3,570

$ 28.01

110,330

D

Phantom Stock Units

$ 0

(2)

(2)

Phantom Stock Units

0

8,461.804 (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		05/26/2005
**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 3,570 shares of stock using 1,671 shares as consideration. This total also reflects a distribution of 30,309 shares of stock from my 401(k) account in connection with my retirement. I also received a cash payment for any fractional shares.
(2)	Phantom stock units will be converted to cash beginning one year after my retirement. I retired effective April 30, 2005.
(3)	I receive phantom stock units as a result of my participation in an excess benefit plan. This total includes 3,579.6038 units in such plan in addition to units held through my account balance in a deferred compensation plan. I also receive dividends.

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