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 * ALLRED ALAN K   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 __X__ Officer (give title below) _____ Other (specify below) Executive Officer (Last) (First) (Middle) 180 EAST 100 SOUTH, P.O. BOX 45433 3. Date of Earliest Transaction (Month/Day/Year) 04/21/2006 (Street) SALT LAKE CITY, UT 84145-0433 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 04/21/2006   M   163 A $ 19.125 29,589 D   Common Stock and attached Common Stock Purchase Rights 04/21/2006   M   1,489 A $ 21.375 31,078 D   Common Stock and attached Common Stock Purchase Rights 04/21/2006   M   2,602 A $ 17 33,680 D   Common Stock and attached Common Stock Purchase Rights 04/21/2006   M   5,950 A $ 15 39,630 D   Common Stock and attached Common Stock Purchase Rights 04/21/2006   S   10,204 (1) D $ 77 29,426 D   Common Stock and attached Common Stock Purchase Rights               22,254.865 I Employee Investment Plan

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

Stock Option

$ 19.125

04/21/2006

M

163

08/11/1997

02/11/2007

Common Stock and attached Common Stock Purchase Rights

163

$ 19.125

6,837

D

Stock Option

$ 21.375

04/21/2006

M

1,489

08/10/1998

02/10/2008

Common Stock and attached Common Stock Purchase Rights

1,489

$ 21.375

6,511

D

Stock Option

$ 17

04/21/2006

M

2,602

08/09/1999

02/09/2009

Common Stock and attached Common Stock Purchase Rights

2,602

$ 17

5,398

D

Stock Option

$ 15

04/21/2006

M

5,950

08/08/2000

02/08/2010

Common Stock and attached Common Stock Purchase Rights

5,950

$ 15

9,050

D

Phantom Stock Units

$ 0

(2)

(2)

Phantom Stock Units

0

1,295.7388 (3)

D

Stock Option

$ 28.01

08/13/2001

02/13/2011

Common Stock and attached Common Stock Purchase Rights

18,000

18,000

D

Stock Option

$ 22.95

08/11/2002

02/11/2012

Common Stock and attached Common Stock Purchase Rights

22,000

22,000

D

Stock Option

$ 27.11

08/11/2003

02/11/2013

Common Stock and attached Common Stock Purchase Rights

52,500

52,500

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
ALLRED ALAN K 180 EAST 100 SOUTH, P.O. BOX 45433 SALT LAKE CITY, UT 84145-0433			Executive Officer

Signatures

Abigail L. Jones Attorney in Fact for A.K. Allred		04/24/2006
**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)	These shares were sold pursuant to a Rule 10b5-1 plan entered into on 3/3/2006 and that was disclosed by my Form 144 filed on 4/21/2006.
(2)	Phantom stock units will be converted to cash beginning at retirement; my retirement date is unknown.
(3)	I also receive phantom stock units as a result of my participation in an excess benefit plan. I have 1,248.2470 shares in it in addition to my shares in a deferred compensation plan. I also receive dividends.

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.