Exhibit 5.1


                    SKADDEN, ARPS, SLATE, MEAGHER & FLOM LLP
                                919 THIRD AVENUE
                               NEW YORK, NY 10022
                                 (212) 735-3000


                                                                December 3, 1999


Edison Mission Holdings Co.
18101 Von Karman Avenue
Irvine, California 92612

                           Re:      Edison Mission Holdings Co.
                                    Registration Statement on Form S-4
                                    ----------------------------------
Ladies and Gentlemen:

                  We are acting as special counsel to Edison Mission Holdings
Co., a California corporation (the "Company"), in connection with the public
offering of $300,000,000 aggregate principal amount of the Company's 8.137%
Senior Secured Bonds due 2019 and of $530,000,000 aggregate principal amount of
the Company's 8.734% Senior Secured Bonds due 2026 (collectively, the "Exchange
Bonds"), which are to be guaranteed, on a senior secured basis pursuant to
guarantees (the "Guarantees" and, together with the Exchange Bonds, the
"Securities") by Edison Mission Finance Co., a California corporation ("Edison
Finance"), Homer City Property Holdings, Inc., a California corporation ("Homer
City Property"), Mission Energy Westside, Inc., a California corporation
("Mission Energy Westside"), Chestnut Ridge Energy Company, a California
corporation ("Chestnut Ridge"), Edison Mission Energy, a California corpora tion
(collectively with Edison Finance, Homer City Property, Mission Energy Westside
and Chestnut Ridge, the "California Subsidiaries"), and EME Homer City
Generation L.P., a Pennsylvania limited partnership ("EME Homer City" and,
collectively with the California Subsidiaries, the "Guarantors"). The Securities
are to be issued pursuant to an exchange offer (the "Exchange Offer") in
exchange for a like principal amount of the issued and outstanding 8.137% Senior
Secured Bonds due 2019 and 8.734% Senior Secured Bonds due 2026 of the Company
(collectively, the "Original Securities") under the Indenture dated as of May
27, 1999 (the "Indenture"), between the Company and United States Trust Company
of New York, as Trustee (the "Trustee"), as contemplated by the Registration
Rights Agreement, dated as of May 27, 1999 (the "Registration






Edison Mission Holdings Co.
December 3, 1999
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Rights Agreement"), by and among the Company, Lehman Brothers Inc., Credit
Suisse First Boston Corporation, Salomon Smith Barney Inc. and SG Cowen
Securities Corp.

                  This opinion is being furnished in accordance with the
requirements of Item 601(b)(5) of Regulation S-K under the Securities Act of
1933, as amended (the "Act").

                  In connection with this opinion, we have examined originals or
copies, certified or otherwise identified to our satisfaction, of (i) the
Registration Statement on Form S-4 relating to the Securities to be filed with
the Securities and Exchange Commis sion (the "Commission") on the date hereof
under the Act (the "Registration Statement"); (ii) an executed copy of the
Registration Rights Agreement; (iii) an executed copy of the Indenture; (iv) the
Articles of Incorporation of the Company and each of the California Subsidiaries
as amended to date; (v) the By-Laws of the Company and each of the California
Subsidiaries as amended to date; (vi) certain resolutions adopted by the Board
of Directors of the Company relating to the Exchange Offer, the issuance of the
Original Securities and the Securities, the Indenture and related matters; (vii)
certain resolutions adopted by the Boards of Directors of each of the California
Subsidiaries relating to, among other things the issuance of the Guarantees by
the California Subsidiaries; (viii) the Form T-1 of the Trustee filed as an
exhibit to the Registration Statement; and (ix) the form of the Securities. We
have also examined originals or copies, certified or otherwise identified to our
satisfaction, of such records of the Company and each of the California
Subsidiaries and such agreements, certificates of public officials, certificates
of officers or other representatives of the Company and each of the California
Subsidiaries and others, and such other documents, certificates and records as
we have deemed necessary or appropriate as a basis for the opinions set forth
herein.

                  In our examination, we have assumed the legal capacity of all
natural persons, the genuineness of all signatures, the authenticity of all
documents submitted to us as originals, the conformity to original documents of
all documents submitted to us as certified, conformed or photostatic copies and
the authenticity of the originals of such latter documents. In making our
examination of executed documents or documents to be executed, we have assumed
that the parties thereto, other than the Company and the California
Subsidiaries, had or will have the power, corporate or other, to enter into and






Edison Mission Holdings Co.
December 3, 1999
Page 3


perform all obligations thereunder and have also assumed the due authorization
by all requisite action, corporate or other, and execution and delivery by such
parties of such documents and the validity and binding effect thereof on such
parties. As to any facts material to the opinions expressed herein which we have
not independently established or verified, we have relied upon statements and
representations of officers and other representatives of the Company, the
Guarantors and others.

                  Our opinion set forth herein is limited to California
corporate law and the laws of the State of New York which are normally
applicable to transactions of the type contemplated by the Exchange Offer and to
the extent that judicial or regulatory orders or decrees or consents, approvals,
licenses, authorizations, validations, filings, recordings or registrations with
governmental authorities are relevant, to those required under such laws (all of
the foregoing being referred to as "Opined on Law"). We do not express any
opinion with respect to the law of any jurisdiction other than Opined on Law or
as to the effect of any such law on the opinions herein stated.

                  Based upon and subject to the foregoing and the limitations,
qualifications, exceptions and assumptions set forth herein, we are of the
opinion that when the Securi ties (in the form examined by us) have been duly
executed and authenticated in accor dance with the terms of the Indenture and
have been delivered upon consummation of the Exchange Offer against receipt of
Old Securities surrendered in exchange therefor in accordance with the terms of
the Exchange Offer, the Securities will constitute valid and binding obligations
of the Company and each of the California Subsidiaries, enforceable against the
Company and each of the California Subsidiaries in accordance with their terms,
except to the extent that enforcement thereof may be limited by (1) bankruptcy,
insolvency, reorganization, moratorium, fraudulent conveyance or other similar
laws now or hereafter in effect relating to creditors' rights generally and (2)
general principles of equity (regardless of whether enforceability is considered
in a proceeding at law or in equity).

                  In rendering the opinion set forth above, we have assumed that
the execution and delivery by the Company and each of the California
Subsidiaries of the Indenture and the Securities and the performance by the
Company and each of the California Subsidiaries of their obligations thereunder
do not and will not violate, conflict






Edison Mission Holdings Co.
December 3, 1999
Page 4

with or constitute a default under any agreement or instrument to which the
Company or the California Subsidiaries or their respective properties is
subject, except that we do not make this assumption for those agreements and
instruments which have been identified to us by the Company or the California
Subsidiaries as being material to them and which are listed as exhibits to the
Registration Statement.

                  We hereby consent to the filing of this opinion with the
Commission as an exhibit to the Registration Statement. We also consent to the
reference to our firm under the caption "Legal Matters" in the Registration
Statement. In giving this consent, we do not thereby admit that we are included
in the category of persons whose consent is required under Section 7 of the Act
or the rules and regulations of the Commission.

                                     Very truly yours,

                                     /s/ SKADDEN, ARPS, SLATE, MEAGHER
                                             & FLOM LLP