BOSTON Latham & Watkins NEW YORK CHICAGO ATTORNEYS AT LAW NORTHERN VIRGINIA FRANKFURT www.lw.com ORANGE COUNTY HAMBURG PARIS HONG KONG ____________________ SAN DIEGO LONDON SAN FRANCISCO LOS ANGELES SILICON VALLEY MOSCOW SINGAPORE NEW JERSEY TOKYO WASHINGTON, D.C. Exhibit 5.1 April 23, 2002 File No. 033446-0001 Compass Minerals Group, Inc. 8300 College Boulevard Overland Park, Kansas 66210 Re: Registration Statement No. 333-82700; $325,000,000 Principal Amount of 10% Senior Subordinated Notes due 2011 ---------------------------------------------------------- Ladies and Gentlemen: In connection with the registration of $325,000,000 aggregate principal amount of 10% Senior Subordinated Notes due August 15, 2011 (the "Exchange Notes") by Compass Minerals Group, Inc., a Delaware corporation (the "Company'), and the guarantees of the Exchange Notes (the "Guarantees") by Carey Salt Company, a Delaware corporation, Great Salt Lake Minerals Corporation, a Delaware corporation, North American Salt Company, a Delaware corporation, NAMSCO Inc., a Delaware corporation, and GSL Corporation, a Delaware corporation (the "Guarantors"), under the Securities Act of 1933, as amended (the "Act"), on Form S-4 filed with the Securities and Exchange Commission (the "Commission") on February 13, 2002 (File No. 333-82700), as amended by Amendment No. 1 filed with the Commission on April 23, 2002 (collectively, the "Registration Statement"), you have requested our opinion with respect to the matters set forth below. In our capacity as your counsel in connection with such registration, we are familiar with the proceedings taken by the Company and the Guarantors in connection with the authorization and issuance of the Exchange Notes and the Guarantees, respectively. In addition, we have made such legal and factual examinations and inquiries, including an examination of originals or copies certified or otherwise identified to our satisfaction of such documents, corporate records and instruments, as we have deemed necessary or appropriate for purposes of this opinion. In our examination, we have assumed the genuineness of all signatures, the authenticity of all documents submitted to us as originals, and the conformity to authentic original documents of all documents submitted to us as copies. We are opining herein as to the effect on the subject transaction only of the federal laws of the United States, the internal laws of the State of New York and the General Corporation Law of the State of Delaware, and we express no opinion with respect to the applicability thereto, or the effect thereon, of the laws of any other jurisdiction or, in the case of Delaware any other laws, or as to any matters of municipal law or the laws of any local agencies within any state. - -------------------------------------------------------------------------------- 53rd at Third o 885 Third Avenue o New York, New York 10022-4802 TELEPHONE: (2I2) 906-1200 o FAX: (2I2) 751-4864 LATHAM & WATKINS Compass Minerals Group, Inc. April 23, 2002 Page 2 Capitalized terms used herein without definition have the meanings ascribed to them in the Registration Statement. Subject to the foregoing and the other matters set forth herein, it is our opinion that as of the date hereof: (1) The Exchange Notes have been duly authorized by all necessary corporate action of the Company, and when executed, authenticated and delivered by or on behalf of the Company against the due tender and delivery to the Trustee of the Old Notes in an aggregate principal amount equal to the aggregate principal amount of the Exchange Notes, will constitute legally valid and binding obligations of the Company, enforceable against the Company in accordance with their terms. (2) Each of the Guarantees has been duly authorized by all necessary corporate action of the respective Guarantor, and when executed in accordance with the terms of the Indenture and upon due execution, authentication and delivery of the Exchange Notes against the due tender and delivery to the Trustee of the Old Notes in an aggregate principal amount equal to the aggregate principal amount of the Exchange Notes, will be the legally valid and binding obligation of the respective Guarantor, enforceable against such Guarantor in accordance with its terms. The opinions rendered in paragraphs 1 and 2 relating to the enforceability of the Exchange Notes and the Guarantees are subject to the following exceptions, limitations and qualifications: (i) the effect of bankruptcy, insolvency, reorganization, moratorium or other similar laws now or hereafter in effect relating to or affecting the rights and remedies of creditors and (ii) the effect of general principles of equity, whether enforcement is considered in a proceeding in equity or law, and the discretion of the court before which any proceeding therefor may be brought. We have not been requested to express, and with your knowledge and consent, do not render any opinion as to the applicability to the obligations of the Company under the Indenture and the Exchange Notes or the Guarantors under the Indenture or the Guarantees of Section 548 of the United States Bankruptcy Code or applicable state law (including, without limitation, Article 10 of the New York Debtor and Creditor Law) relating to fraudulent transfers and obligations. To the extent that the obligations of the Company and the Guarantors under the Indenture may be dependent upon such matters, we assume for purposes of this opinion that the Trustee is duly organized, validly existing and in good standing under the laws of its jurisdiction of organization; that the Trustee is duly qualified to engage in the activities contemplated by the Indenture; that the Indenture has been duly authorized, executed and delivered by the Trustee and constitutes the legally valid, binding and enforceable obligation of the Trustee enforceable against the Trustee in accordance with its terms; that the Trustee is in compliance, generally and LATHAM & WATKINS Compass Minerals Group, Inc. April 23, 2002 Page 3 with respect to acting as a trustee under the Indenture, with all applicable laws and regulations; and that the Trustee has the requisite organizational and legal power and authority to perform its obligations under the Indenture. We consent to your filing this opinion as an exhibit to the Registration Statement and to the reference to our firm contained under the heading "Legal Matters." Truly yours, /s/ Latham & Watkins