Ownership Submission
FORM 3
 UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF 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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(Print or Type Responses)
1. Name and Address of Reporting Person *
  CAMPBELL REID TARLTON
 2. Date of Event Requiring Statement (Month/Day/Year)
05/24/2007		 3. Issuer Name and Ticker or Trading Symbol
WHITE MOUNTAINS INSURANCE GROUP LTD [WTM]
(Last)
(First)
(Middle)
C/O WHITE MOUNTAINS INSURANCE GROUP, LTD, 80 SOUTH MAIN STREET		 4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Managing Director & President
 5. If Amendment, Date Original Filed(Month/Day/Year)
(Street)

HANOVER, NH 03755		 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 Beneficially Owned
1.Title of Security
(Instr. 4)		 2. Amount of Securities Beneficially Owned
(Instr. 4)		 3. Ownership Form: Direct (D) or Indirect (I)
(Instr. 5)		 4. Nature of Indirect Beneficial Ownership
(Instr. 5)
Common Shares 900
D
 
Common Shares (Restricted) 2,000
D
 
Common Shares 9
I
by 401(k)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 4)		 2. Date Exercisable and Expiration Date
(Month/Day/Year)		 3. Title and Amount of Securities Underlying Derivative Security
(Instr. 4)		 4. Conversion or Exercise Price of Derivative Security 5. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 5)		 6. Nature of Indirect Beneficial Ownership
(Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares
Common Share Options   (1) 02/28/2010 Common Shares 2,700 $ (2) D  

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
CAMPBELL REID TARLTON
C/O WHITE MOUNTAINS INSURANCE GROUP, LTD
80 SOUTH MAIN STREET
HANOVER, NH 03755		       Managing Director & President  

Signatures

Jason R. Lichtenstein, by Power of Attorney 06/01/2007
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 5(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) Options to acquire 900 Common Shares become exercisable on each of December 27, 2007, December 27, 2008 and December 27, 2009.
(2) The Options were originally awarded on February 28, 2000 at an initial exercise price of $106.19. The exercise price increases by 6% annually on a cumulative basis.

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

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