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                                                                     EXHIBIT 5.1



                       [HAYNES AND BOONE, LLP LETTERHEAD]



April 7, 1999


Sunshine Mining and Refining Company
877 W. Main Street, Suite 600
Boise, Idaho 83702

Re:      Registration of 9,000,000 Shares of Common Stock

Gentlemen:

We have acted as counsel to Sunshine Mining and Refining Company, a Delaware
corporation (the "Company"), in connection with the preparation and filing by
the Company with the Securities and Exchange Commission of a Registration
Statement on Form S-3 (SEC File No. 333-74437) (as amended, the "Registration
Statement") under the Securities Act of 1933, as amended. The Registration
Statement registers the proposed offer and sale by certain stockholders of the
Company (the "Selling Stockholders") of up to 19,000,000 shares (the "Shares")
of the Company's common stock, par value $0.01 per share ("Common Stock"), to be
issued upon the conversion of the Company's currently outstanding 5% Convertible
Notes (the "Notes").

   
In connection therewith, we have examined and relied upon the originals, or
copies certified to our satisfaction, of (i) the Certificate of Incorporation of
the Company, as amended (the "Certificate of Incorporation"); (ii) the Bylaws of
the Company (the "Bylaws"); (iii) the minutes and records of the corporate
proceedings of the Company with respect to the issuance and sale of the Notes
and the issuance of the Shares; (iv) the Registration Statement and all exhibits
thereto; (v) the Notes; (vi) the specimen Common Stock certificate filed as
Exhibit 4.2 to the Company's Registration Statement on Form S-1 (Reg. No.
33-63446); and (vii) such other documents and instruments as we have deemed
necessary for the expression of the opinions contained herein, including the
Registration Rights Agreement, dated as of January 28, 1999, by and among the
Company and the Selling Stockholders, and the Investment Agreement, dated as of
January 27, 1999, among the Company and the Selling Stockholders (the
Registration Rights Agreement and the Investment Agreement are collectively
referred to as the "Related Documents").
    

In making the foregoing examinations, we have assumed the genuineness of all
signatures and the authenticity of all documents submitted to us as originals,
and the conformity to original documents of all documents submitted to us as
certified or photostatic copies thereof and the authenticity of the originals of
such latter documents. As to various questions of fact material to this opinion,
where such facts have not been independently established, and as to the content
and form of the Certificate of Incorporation, the Bylaws, 


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Sunshine Mining and Refining Company
April 7, 1999
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certain minutes, records, resolutions and other documents or writings of the
Company, we have relied, to the extent we have deemed reasonably appropriate,
upon representations or certificates of officers of the Company or governmental
officials and upon documents, records, and instruments furnished to us by the
Company, without independent check or verification of their accuracy. Finally,
we have assumed that all formalities required by the Certificate of
Incorporation, Bylaws and the General Corporation Law of the State of Delaware
will be complied with when the Shares are issued.

   
Based upon the foregoing and subject to the limitations, qualifications,
exceptions and assumptions set forth herein and having due regard for such legal
considerations as we deem relevant, we are of the opinion that the Shares to be
issued by the Company upon the conversion of the Notes have been duly authorized
and, when issued in accordance with the terms of the Notes and the Related
Documents, will be validly issued, fully paid and non-assessable.
    

The opinions expressed above are specifically limited to the General Corporation
Laws, as amended, of the State of Delaware, and the federal laws of the United
States of America.

This opinion (i) is rendered as of the date hereof, and we undertake no, and
hereby disclaim any kind of, obligation to advise you of any change or any new
developments that might affect any matters or opinions set forth herein, and
(ii) is limited to the matters stated herein and no opinions may be inferred or
implied beyond the matters expressly stated herein.

We hereby consent to the filing of this opinion with the Securities and Exchange
Commission as an exhibit to the Registration Statement and to the reference to
this firm under "Legal Matters" in the Prospectus forming a part of such
Registration Statement.


Very truly yours,

/s/Haynes and Boone, LLP

Haynes and Boone, LLP