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
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(Print or Type Responses)
1. Name and Address of Reporting Person *
LAMSON STEPHEN B
  2. Issuer Name and Ticker or Trading Symbol
SIMPSON MANUFACTURING CO INC /CA/ [NYSE:SSD]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Pres/COO Simpson Strong-Tie Co
(Last)
(First)
(Middle)
4120 DUBLIN BLVD., SUITE 400
3. Date of Earliest Transaction (Month/Day/Year)
03/29/2005
(Street)

DUBLIN, CA 94568
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               155,808 D  
Common Stock               5,516 (2) I By Trust

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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
Options on Common Stock $ 34.9 03/29/2005   A   6,000   01/01/2006(1) 12/31/2011 Common Stock 6,000 $ 34.9 6,000 D  
Options on Common Stock $ 16.45             01/01/2004(1) 12/31/2009 Common Stock 12,000   12,000 D  
Options on Common Stock $ 25.43             01/01/2005(1) 12/31/2010 Common Stock 12,000   12,000 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
LAMSON STEPHEN B
4120 DUBLIN BLVD., SUITE 400
DUBLIN, CA 94568
  X     Pres/COO Simpson Strong-Tie Co  

Signatures

 Stephen B. Lamson   03/29/2005
**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) This date represents the date of the first annual vesting period. This option vests equally over four year beginning with the date of grant.
(2) The shares are owned by the Simpson Manufacuturing Co., Inc. Profit Sharing Plan for Salaried Employees (the "Plan") of which the reporting person is a participant. The Plan is qualified under sections 401(a)(26) and 410 of the Internal Revenue Code. The number of shares owned by the reporting person is based on a recent statement.

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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