SC 13G/A

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13G

Under the Securities Exchange Act of 1934
(Amendment No. 7)*

CANADIAN NATIONAL RAILWAY COMPANY

(Name of Issuer)

Common Shares

(Title of Class of Securities)

136375102

(CUSIP Number)

December 31, 2006

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

o	Rule 13d-1(b)
ý	Rule 13d-1(c)
o	Rule 13d-1(d)

*The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

CUSIP No. 136375102
	1.	Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only) Cascade Investment, L.L.C.
	2.	Check the Appropriate Box if a Member of a Group (See Instructions)
		(a)		o
		(b)		ý
	3.	SEC Use Only
	4.	Citizenship or Place of Organization State of Washington
Number of Shares Beneficially Owned by Each Reporting Person With			5.		Sole Voting Power 31,434,745*
			6.		Shared Voting Power -0-
			7.		Sole Dispositive Power 31,434,745*
			8.		Shared Dispositive Power -0-
	9.	Aggregate Amount Beneficially Owned by Each Reporting Person 31,434,745*
	10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)  o
	11.	Percent of Class Represented by Amount in Row (9) 6.1%
	12.	Type of Reporting Person (See Instructions) OO

* The number of shares reflects a 2-for-1 stock split of the Issuer’s Common Shares that was effected on February 28, 2006.

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	1.	Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only) Bill & Melinda Gates Foundation Trust
	2.	Check the Appropriate Box if a Member of a Group (See Instructions)
		(a)		o
		(b)		ý
	3.	SEC Use Only
	4.	Citizenship or Place of Organization State of Washington
Number of Shares Beneficially Owned by Each Reporting Person With			5.		Sole Voting Power -0-
			6.		Shared Voting Power 5,490,855*
			7.		Sole Dispositive Power -0-
			8.		Shared Dispositive Power 5,490,855*
	9.	Aggregate Amount Beneficially Owned by Each Reporting Person 5,490,855*
	10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)  o
	11.	Percent of Class Represented by Amount in Row (9) 1.0%
	12.	Type of Reporting Person (See Instructions) OO

* For purposes of Rule 13d-3 under the Securities Exchange Act of 1934, as amended, all Common Shares held by the Bill & Melinda Gates Foundation Trust (the “Trust”) may be deemed to be beneficially owned by William H. Gates III and Melinda French Gates as Co-Trustees of the Trust.  Michael Larson acts with investment discretion for Mr. and Mrs. Gates, as Co-Trustees of the Trust, in respect of the Common Shares owned by the Trust.  Mr. Larson disclaims any beneficial ownership of the Common Shares beneficially owned by the Trust or Mr. and Mrs. Gates.  The number of shares reflects a 2-for-1 stock split of the Issuer’s Common Shares that was effected on February 28, 2006.

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	1.	Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only) Melinda French Gates
	2.	Check the Appropriate Box if a Member of a Group (See Instructions)
		(a)		o
		(b)		ý
	3.	SEC Use Only
	4.	Citizenship or Place of Organization United States of America
Number of Shares Beneficially Owned by Each Reporting Person With			5.		Sole Voting Power -0-
			6.		Shared Voting Power 5,490,855*
			7.		Sole Dispositive Power -0-
			8.		Shared Dispositive Power 5,490,855*
	9.	Aggregate Amount Beneficially Owned by Each Reporting Person 5,490,855*
	10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)  o
	11.	Percent of Class Represented by Amount in Row (9) 1.0%
	12.	Type of Reporting Person (See Instructions) IN

* For purposes of Rule 13d-3 under the Securities Exchange Act of 1934, as amended, all Common Shares held by the Bill & Melinda Gates Foundation Trust (the “Trust”) may be deemed to be beneficially owned by William H. Gates III and Melinda French Gates as Co-Trustees of the Trust.  Michael Larson acts with investment discretion for Mr. and Mrs. Gates, as Co-Trustees of the Trust, in respect of the Common Shares owned by the Trust.  Mr. Larson disclaims any beneficial ownership of the Common Shares beneficially owned by the Trust or Mr. and Mrs. Gates.  The number of shares reflects a 2-for-1 stock split of the Issuer’s Common Shares that was effected on February 28, 2006.

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	1.	Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only) William H. Gates III
	2.	Check the Appropriate Box if a Member of a Group (See Instructions)
		(a)		o
		(b)		ý
	3.	SEC Use Only
	4.	Citizenship or Place of Organization United States of America
Number of Shares Beneficially Owned by Each Reporting Person With			5.		Sole Voting Power 31,434,745*
			6.		Shared Voting Power 5,490,855*
			7.		Sole Dispositive Power 31,434,745*
			8.		Shared Dispositive Power 5,490,855*
	9.	Aggregate Amount Beneficially Owned by Each Reporting Person 36,925,600*
	10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)  o
	11.	Percent of Class Represented by Amount in Row (9) 7.1%
	12.	Type of Reporting Person (See Instructions) IN

* All Common Shares held by Cascade Investment, L.L.C. (“Cascade”) may be deemed to be beneficially owned by William H. Gates III as the sole member of Cascade.  For purposes of Rule 13d-3 under the Securities Exchange Act of 1934, as amended, all Common Shares held by the Bill & Melinda Gates Foundation Trust (the “Trust”) may be deemed to be beneficially owned by William H. Gates III and Melinda French Gates as Co-Trustees of the Trust.  Michael Larson, the Business Manager of Cascade, has voting and investment power with respect to the Common Shares held by Cascade.  In addition, Mr. Larson acts with investment discretion for Mr. and Mrs. Gates, as Co-Trustees of the Trust, in respect of the Common Shares owned by the Trust.  Mr. Larson disclaims any beneficial ownership of the Common Shares beneficially owned by Cascade, the Trust or Mr. and Mrs. Gates.  The number of shares reflects a 2-for-1 stock split of the Issuer’s Common Shares that was effected on February 28, 2006.

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Item 1.
	(a)	Name of Issuer Canadian National Railway Company (the “Issuer”)
	(b)	Address of Issuer’s Principal Executive Offices 935 de la Gauchetiere St. West, Montreal, Quebec, Canada H3B 2M9
Item 2.
	(a)	Name of Person Filing Cascade Investment, L.L.C. (“Cascade”), Bill & Melinda Gates Foundation Trust (the “Trust”), Melinda French Gates and William H. Gates III. *
	(b)	Address of Principal Business Office or, if none, Residence Cascade – 2365 Carillon Point, Kirkland, Washington 98033 The Trust – 1551 Eastlake Avenue E., Seattle, Washington 98102 Mr. Gates – One Microsoft Way, Redmond, Washington 98052 Mrs. Gates – 2365 Carillon Point, Kirkland, Washington 98033
	(c)	Citizenship Cascade is a limited liability company organized under the laws of the State of Washington. The Trust is a charitable trust organized under the laws of the State of Washington. Both Mr. and Mrs. Gates are citizens of the United States of America.
	(d)	Title of Class of Securities Common Shares
	(e)	CUSIP Number 136375102

*Neither the present filing nor anything contained herein shall be construed as an admission that Cascade, the Trust or Mr.and Mrs. Gates constitute a “person” for any purpose other than Section 13(g) of the Securities Exchange Act of 1934, or that Cascade, the Trust and Mr. and Mrs. Gates constitute a “group” for any purpose.

Item 3.	If this statement is filed pursuant to §§240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
	(a)	o	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o).
	(b)	o	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c).
	(c)	o	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c).
	(d)	o	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C 80a-8).
	(e)	o	An investment adviser in accordance with §240.13d-1(b)(1)(ii)(E);
	(f)	o	An employee benefit plan or endowment fund in accordance with §240.13d-1(b)(1)(ii)(F);
	(g)	o	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
	(h)	o	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
	(i)	o	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
	(j)	o	Group, in accordance with §240.13d-1(b)(1)(ii)(J).
	Not Applicable.

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Item 4.	Ownership
Provide the following information regarding the aggregate number and percentage of the class of securities of the issuer identified in Item 1.
	(a)	Amount beneficially owned:    See the responses to Item 9 on the attached cover pages.
	(b)	Percent of class:    See the responses to Item 11 on the attached cover pages.
	(c)	Number of shares as to which the person has:
		(i)	Sole power to vote or to direct the vote    See the responses to Item 5 on the attached cover pages.
		(ii)	Shared power to vote or to direct the vote     See the responses to Item 6 on the attached cover pages.
		(iii)	Sole power to dispose or to direct the disposition of    See the responses to Item 7 on the attached cover pages.
		(iv)	Shared power to dispose or to direct the disposition of    See the responses to Item 8 on the attached cover pages.
Item 5.	Ownership of Five Percent or Less of a Class
If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following   o.
	Not Applicable.
Item 6.	Ownership of More than Five Percent on Behalf of Another Person
	Not Applicable.
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company or Control Person
	Not Applicable.
Item 8.	Identification and Classification of Members of the Group
	See Exhibit 99.1.
Item 9.	Notice of Dissolution of Group
	Not Applicable.
Item 10.	Certification
	By signing below I certify theat, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.

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SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Date:  February 14, 2007
CASCADE INVESTMENT, L.L.C.(1)
By	/s/ Michael Larson
	Name:	Michael Larson
	Title:	Business Manager
BILL & MELINDA GATES FOUNDATION TRUST(1)
By	/s/ Michael Larson
	Name:	Michael Larson (2)
	Title:	Attorney-in-fact for each of the Co-Trustees, William
		H. Gates III and Melinda French Gates
WILLIAM H. GATES III(1)
By	/s/ Michael Larson
	Name:	Michael Larson (2) (3)
	Title:	Attorney-in-fact
MELINDA FRENCH GATES(1)
By	/s/ Michael Larson
	Name:	Michael Larson (2)
	Title:	Attorney-in-fact

(1)   This amendment is being filed jointly by Cascade Investment, L.L.C., the Bill & Melinda Gates Foundation Trust, William H. Gates III, and Melinda French Gates pursuant to the Joint Filing Agreement dated February 14, 2006 and included with the signature page to Cascade Investment, L.L.C.’s Amendment No. 6 to Schedule 13G with respect to Canadian National Railway Company on February 15, 2006, SEC File No. 005-48661, and incorporated by reference herein.

(2)   Duly authorized under Special Power of Attorney appointing Michael Larson attorney-in-fact, dated November 13, 2006, by and on behalf of William H. Gates III and Melinda French Gates as Co-Trustees, filed as Exhibit 99.1 to the Bill & Melinda Gates Foundation Trust’s Amendment No. 3 to Schedule 13G with respect to Coca-Cola FEMSA, S.A. de C.V. on February 13, 2007, SEC File No. 005-52421, and incorporated by reference herein.

(3)   Duly authorized under Special Power of Attorney appointing Michael Larson attorney-in-fact, dated February 3, 2006, by and on behalf of William H. Gates III, filed as Exhibit 99.1 to Cascade Investment, L.L.C.’s Amendment No. 2 to Schedule 13G with respect to Arch Capital Group Ltd. on March 7, 2006, SEC File No. 005-45257, and incorporated by reference herein.

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EX-99.1

EXHIBIT 99.1

ITEM 8 INFORMATION

The following may be deemed to be members of a group for purposes of this joint filing of a statement on Schedule 13G:

Cascade Investment, L.L.C., a limited liability company organized under the laws of the State of Washington; Bill & Melinda Gates Foundation Trust, a charitable trust organized under the laws of the State of Washington; William H. Gates III, a citizen of the United States of America; and Melinda French Gates, a citizen of the United States of America.