EXHIBIT
      4.1




**MIDAMERICAN
      ENERGY COMPANY**




and




**THE
      BANK OF NEW YORK TRUST COMPANY, NA,**




as
      Trustee




________________




5.750%
      Notes due 2035




________________




Fourth
      Supplemental Indenture




________________




Dated
      as
      of November 1, 2005

















FOURTH
      SUPPLEMENTAL INDENTURE, dated as of November 1, 2005 (herein called the
“ Fourth
      Supplemental Indenture ”),
      between MIDAMERICAN ENERGY COMPANY, a corporation duly organized and existing
      under the laws of the State of Iowa (herein called the “ Company ”),
      and
      THE BANK OF NEW YORK TRUST COMPANY, NA (as successor to The Bank of New York),
      a
      New York banking association duly organized and existing under the laws of
      the
      United States of America, as Trustee (herein called the “ Trustee ”),
      under
      the Original Indenture referred to below.




W
      I T N E
      S S E T H :




WHEREAS,
      the Company has heretofore executed and delivered to the Trustee an indenture
      dated as of February 8, 2002, as amended (herein called the “ Original
      Indenture ”),
      as
      supplemented by the First Supplemental Indenture dated as of February 8, 2002,
      the Second Supplemental Indenture dated as of January 14, 2003 and the Third
      Supplemental Indenture dated as of October 1, 2004, to provide for the issuance
      from time to time of its unsubordinated debentures, notes or other evidences
      of
      indebtedness, the form and terms of which are to be established as set forth
      in
      Sections 2.01 and 3.01 of the Original Indenture;




WHEREAS,
      Section 9.01 of the Original Indenture provides, among other things, that the
      Company and the Trustee may enter into indentures supplemental to the Original
      Indenture for, among other things, (i) the purpose of establishing the form
      and
      terms of the Securities (as defined in the Original Indenture) of any series
      as
      permitted by Sections 2.01 and 3.01 of the Original Indenture, and (ii) to
      add
      to the covenants of the Company for the benefit of the Holders of all or any
      series of Securities (as defined in the Original Indenture);




WHEREAS,
      the Company desires to create one series of securities to be designated the
      “5.750% Notes due 2035” and all action on the part of the Company necessary to
      authorize the issuance of up to three hundred million dollars ($300,000,000)
      aggregate principal amount of such securities (the “ Securities ”)
      under
      the Original Indenture and this Fourth Supplemental Indenture has been duly
      taken;




WHEREAS,
      the Company and the Trustee desire to make certain amendments to the Original
      Indenture in conformance with the requirements described above; and




WHEREAS,
      all acts and things necessary to make the Securities, when executed by the
      Company and authenticated and delivered by the Trustee as provided in the
      Original Indenture, the valid and binding obligations of the Company and to
      constitute these presents a valid and binding supplemental indenture and
      agreement according to its terms, have been done and performed.






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NOW,
      THEREFORE, THIS FOURTH SUPPLEMENTAL INDENTURE WITNESSETH:




That
      in
      consideration of the premises and of the acceptance and purchase of the
      Securities by the holders thereof and of the acceptance of this trust by the
      Trustee, the Company covenants and agrees with the Trustee, for the equal
      benefit of holders of the Securities, as follows:




ARTICLE
      I




DEFINITIONS




Unless
      otherwise defined herein, the use of the terms and expressions herein is in
      accordance with the definitions, uses and constructions contained in the
      Original Indenture and the form of Security attached hereto as Exhibit
      A .




ARTICLE
      II




TERMS
      AND
      ISSUANCE OF THE SECURITIES




Section
      2.01. *Issue
      of Securities* .
      One
      series of notes, which shall be designated the “5.750% Notes due 2035”, shall be
      executed, authenticated and delivered in accordance with the provisions of,
      and
      shall in all respects be subject to, the terms, conditions and covenants of
      the
      Original Indenture and this Fourth Supplemental Indenture (including the form
      of
      Security set forth in Exhibit
      A ).




Section
      2.02. *Optional
      Redemption* .
      The
      Securities may be redeemed, in whole or in part, at the option of the Company
      pursuant to the terms set forth in Annex
      1 to the
      Securities to be redeemed. The provisions of Article XI of the Original
      Indenture shall also apply to any optional redemption of Securities by the
      Company.




Section
      2.03. *Defeasance
      and Discharge* .
      The
      provisions of Section 14.02 of the Original Indenture shall be applicable to
      the
      Securities.




Section
      2.04. *Covenant
      Defeasance* .
      The
      provisions of Section 14.03 of the Original Indenture shall be applicable to
      the
      Securities.




Section
      2.05. *Place
      of Payment* .
      The
      Place of Payment in respect of the Securities will be initially at the Corporate
      Trust Office of The Bank of New York Trust Company, NA (which as of the date
      hereof is located at 2 N. LaSalle Street, Suite 1020, Chicago, Illinois 60602,
      Attention: Corporate Trust Administration).




Section
      2.06. *Form
      of Securities; Incorporation of Terms* .
      The
      form of the Securities shall be substantially in the form of Exhibit
      A ,
      the
      terms of which are herein incorporated by reference and which are part of this
      Fourth Supplemental Indenture. The Securities shall be issued as one or more
      Global Securities in fully registered form, as determined in accordance with
      Section 2.01 of the Original Indenture. The Global Securities shall be delivered
      by the Trustee to the Depositary, as the Holder thereof, or a nominee or
      custodian therefore, to be held by the Depositary in accordance with the
      Original Indenture.






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Section
      2.07. *Exchange
      of the Global Securities* .
      Each of
      the Global Securities shall be exchangeable for definitive Securities only
      as
      provided in Section 3.05 of the Original Indenture.




Section
      2.08. *Regular
      Record Date for the Securities* .
      The
      Regular Record Date for the Securities shall be the April 15 or October 15
      immediately prior to each Interest Payment Date.




Section
      2.09. *Authorized
      Denominations.* Beneficial
      interests in Global Securities, as well as definitive Securities, may be held
      only in denominations of $1,000 and integral multiples of $1,000 in excess
      thereof.




Section
      2.10. *Additional
      Securities.* The
      Company may from time to time, without the consent of the Holders of the
      Securities, create and issue further securities having the same terms and
      conditions as the Securities in all respects, except for the original issue
      date
      and offering price. Additional Securities issued in this manner will be
      consolidated with, and form a single series with, the Securities and shall
      thereafter be deemed Securities for all purposes.




ARTICLE
      III




DEPOSITARY




Section
      3.01. *Depositary* .
      The
      Depositary Trust Company, its nominees and their respective successors are
      hereby appointed Depositary with respect to the Global Securities.




ARTICLE
      IV




AMENDMENTS
      TO ORIGINAL INDENTURE




Section
      4.01. *Amendments* .
      The
      Original Indenture is hereby amended as follows:




(a)  Section
      1.01 of the Original Indenture is hereby amended to add or modify the following
      definitions, as the case may be:




“ ‘Common
      Shareholders’ Equity ’
means,
      at any time, the total shareholders’ equity of the Company and its consolidated
      subsidiaries, determined on a consolidated basis in accordance with generally
      accepted accounting principles, as of the end of the most recently completed
      fiscal quarter of the Company for which financial information is then
      available.”






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“‘ Midwest
      Power Indenture ’
means
      the General Mortgage Indenture and Deed of Trust, dated as of January 1, 1993,
      between Midwest Power Systems Inc. and Morgan Guaranty Trust Company of New
      York, trustee (Harris Trust and Savings Bank, successor trustee), and indentures
      supplemental thereto.”




“‘ Permitted
      Encumbrances ’
      means:




(a)  (i)
      any
      mortgage, pledge or other lien or encumbrance on any property hereafter acquired
      or constructed by the Company or a Subsidiary, or on which property so
      constructed is located, and created prior to, contemporaneously with or within
      360 days after, such acquisition or construction or the commencement of
      commercial operation of such property to secure or provide for the payment
      of
      any part of the purchase or construction price of such property, or (ii) any
      property subject to any mortgage, pledge, or other lien or encumbrance upon
      such
      property existing at the time of acquisition thereof by the Company or any
      Subsidiary, whether or not assumed by the Company or such Subsidiary, or (iii)
      any mortgage, pledge or other lien or encumbrance existing on the property,
      shares of stock, membership interests or indebtedness of a corporation or
      limited liability company at the time such corporation or limited liability
      company shall become a Subsidiary or any pledge of the shares of stock or
      membership interests of such corporation or limited liability company prior
      to,
      contemporaneously with or within 360 days after such corporation or limited
      liability company shall become a Subsidiary to secure or provide for the payment
      of any part of the purchase price of such stock or membership interests, or
      (iv)
      any conditional sales agreement or other title retention agreement with respect
      to any property hereafter acquired or constructed; *provided* that, in
      the case of clauses (i) through (iv), the lien of any such mortgage, pledge
      or
      other lien does not spread to property owned prior to such acquisition or
      construction or to other property thereafter acquired or constructed other
      than
      additions to such acquired or constructed property and other than property
      on
      which property so constructed is located; and *provided,
      further* ,
      that if
      a firm commitment from a bank, insurance company or other lender or investor
      (not including the Company, a Subsidiary or an Affiliate of the Company) for
      the
      financing of the acquisition or construction of property is made prior to,
      contemporaneously with or within the 360-day period hereinabove referred to,
      the
      applicable mortgage, pledge, lien or encumbrance shall be deemed to be permitted
      by this clause (a) whether or not created or assumed within such
      period;






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(b)  any
      mortgage, pledge or other lien or encumbrance created for the sole purpose
      of
      extending, renewing or refunding any mortgage, pledge, lien or encumbrance
      permitted by clause (a) of this definition; *provided,
      however* ,
      that
      the principal amount of indebtedness secured thereby shall not exceed the
      principal amount of indebtedness so secured at the time of such extension,
      renewal or refunding and that such extension, renewal or refunding mortgage,
      pledge, lien or encumbrance shall be limited to all or any part of the same
      property that secured the mortgage, pledge or other lien or encumbrance
      extended, renewed or refunded;




(c)  liens
      for
      taxes or assessments or governmental charges or levies not then due and
      delinquent or the validity of which is being contested in good faith, and
      against which an adequate reserve has been established; liens on any property
      created in connection with pledges or deposits to secure public or statutory
      obligations or to secure performance in connection with bids or contracts;
      materialmen’s, mechanics’, carrier’s, workmen’s, repairmen’s or other like
      liens; or liens on any property created in connection with deposits to obtain
      the release of such liens; liens on any property created in connection with
      deposits to secure surety, stay, appeal or customs bonds; liens created by
      or
      resulting from any litigation or legal proceeding which is currently being
      contested in good faith by appropriate proceedings; leases and liens, rights
      of
      reverter and other possessory rights of the lessor thereunder; zoning
      restrictions, easements, rights-of-way or other restrictions on the use of
      real
      property or minor irregularities in the title thereto; and any other liens
      and
      encumbrances similar to those described in this clause (c), the existence of
      which, in the opinion of the board of directors of the Company, does not
      materially impair the use by the Company or a Subsidiary of the affected
      property in the operation of the business of the Company or a Subsidiary, or
      the
      value of such property for the purposes of such business;




(d)  any
      mortgage, pledge or other lien or encumbrance created after November 1, 2005
      on
      any property leased to or purchased by the Company or a Subsidiary after that
      date and securing, directly or indirectly, obligations issued by a State, a
      territory or a possession of the United States, or any political subdivision
      of
      any of the foregoing, or the District of Columbia, to finance the cost of
      acquisition or cost of construction of such property; *provided* that the
      interest paid on such obligations is entitled to be excluded from gross income
      of the recipient pursuant to Section 103(a)(1) of the Internal Revenue Code
      of
      1986, as amended (or any successor to such provision), as in effect at the
      time
      of the issuance of such obligations;






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(e)  any
      mortgage, pledge or other lien or encumbrance on any property now owned or
      hereafter acquired or constructed by the Company or a Subsidiary, or on which
      property so owned, acquired or constructed is located, to secure or provide
      for
      the payment of any part of the construction price or cost of improvements of
      such property, and created prior to, contemporaneously with or within 360 days
      after, such construction or improvement; *provided* that if
      a firm commitment from a bank, insurance company or other lender or investor
      (not including the Company, a Subsidiary or an Affiliate of the Company) for
      the
      financing of the acquisition or construction of property is made prior to,
      contemporaneously with or within the 360-day period hereinabove referred to,
      the
      applicable mortgage, pledge, lien or encumbrance shall be deemed to be permitted
      by this clause (e) whether or not created or assumed within such period;
      and




(f)  any
      mortgage, pledge or other lien or encumbrance not otherwise described in clauses
      (a) through (e); *provided* that the
      aggregate amount of indebtedness secured by all such mortgages, pledges, liens
      or encumbrances does not exceed the greater of $100,000,000 or 10% of Common
      Shareholders’ Equity.”




“‘ Principal
      Facility ’
means
      the real property, fixtures, machinery and equipment relating to any facility
      owned by the Company or any Subsidiary, except any facility that is not of
      material importance to the business conducted by the Company and its
      Subsidiaries, taken as a whole.”




“‘ Regulated
      Subsidiary ’
means
      any Subsidiary which owns or operates facilities used for the generation,
      transmission or distribution of electric energy and is subject to the
      jurisdiction of any governmental authority of the United States or any state
      or
      political subdivision thereof, as to any of its: rates; services; accounts;
      issuances of securities; affiliate transactions; or construction, acquisition
      or
      sale of any such facilities, except that any ‘exempt wholesale generator’, as
      defined in 15 USC 79z-5a(a)(1), ‘qualifying facility’, as defined in 18 CFR
      292.101(b)(1), ‘foreign utility company’, as defined in 15 USC 79z-5b(a)(3), and
‘power marketer’, as defined in NORTHWEST POWER MARKETING COMPANY, L.L.C., 75
      FERC PARA 61,281, shall not be a Regulated Subsidiary.”






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“‘ Subsidiary ’
means
      a
      corporation or limited liability company more than 50% of the outstanding voting
      stock or voting membership interests of which is or are owned, directly or
      indirectly, by the Company or by one or more other Subsidiaries, or by the
      Company and one or more other Subsidiaries. For the purposes of this definition,
      (1) ‘voting stock’ means stock which ordinarily has voting power for the
      election of directors, whether at all times or only so long as no senior class
      of stock has such voting power by reason of any contingency, and (2) ‘voting
      membership interests’ means membership interests which ordinarily have voting
      power for the election of directors (or the equivalent thereof), whether at
      all
      times or only so long as no senior class of membership interests have such
      voting power by reason of any contingency.”




“‘ Wholly-Owned
      Subsidiary ’
means
      a
      Subsidiary of which all of the outstanding voting stock or voting membership
      interests (other than directors’ qualifying shares) is or are at the time,
      directly or indirectly, owned by the Company, or by one or more Wholly-Owned
      Subsidiaries of the Company or by the Company and one or more Wholly-Owned
      Subsidiaries.”




(b)  Section
      10.06 of the Original Indenture is hereby amended by replacing the reference
      to
      Section 10.04 therein with a reference to Section 10.08.




(c)  Article
      X
      of the Original Indenture is amended by adding a new Section 10.08 thereto
      immediately following Section 10.07 thereof, such Section 10.08 to read as
      follows:




“Section
      10.08. Limitation
      upon Mortgages and Liens .




The
      Company will not at any time directly or indirectly create or assume and will
      not cause or permit a Subsidiary directly or indirectly to create or assume,
      except in favor of the Company or a Wholly-Owned Subsidiary, any mortgage,
      pledge or other lien or encumbrance upon any Principal Facility or any interest
      it may have therein or upon any stock of any Regulated Subsidiary or any
      indebtedness of any Subsidiary to the Company or any other Subsidiary, whether
      now owned or hereafter acquired, without making effective provision (and the
      Company covenants that in such case it will make or cause to be made, effective
      provision) whereby the outstanding Securities and any other indebtedness of
      the
      Company then entitled thereto shall be secured by such mortgage, pledge, lien
      or
      encumbrance equally and ratably with any and all other obligations and
      indebtedness thereby secured, so long as any such other obligations and
      indebtedness shall be so secured (provided, that for the purpose of providing
      such equal and ratable security, the principal amount of outstanding Original
      Issue Discount Securities shall be the amount of the principal thereof that
      would be due and payable as of the date of such determination upon a declaration
      of acceleration of the Maturity thereof pursuant to Section 5.02); *provided,
      however* ,
      that
      the foregoing covenant shall not be applicable to (1) the lien of the Midwest
      Power Indenture, (2) Permitted Encumbrances or (3) any transfer, lease, use
      or
      other encumbrance of or on the Company’s or any Subsidiary’s transmission assets
      as required by applicable state or federal order, regulation, rule or
      statute.”






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(e)  The
      first
      sentence of Section 14.03 of the Original Indenture is hereby amended by
      replacing the references to Section 10.04 therein with references to Section
      10.08 in each place where such references appear in such sentence.




Section
      4.02. *Application
      of Amendments* .
      The
      amendments to the Original Indenture set forth in Section 4.01 hereof shall
      be
      applicable only to the Securities, and shall not be applicable to any other
      series of securities issued under the Original Indenture except as otherwise
      provided in a supplemental indenture related to such other series of
      securities.




ARTICLE
      V


MISCELLANEOUS




Section
      5.01. *Execution
      as Supplemental Indenture* .
      This
      Fourth Supplemental Indenture is executed and shall be construed as an indenture
      supplemental to the Original Indenture and, as provided in the Original
      Indenture, this Fourth Supplemental Indenture forms a part thereof.




Section
      5.02. *Effect
      of Headings* .
      The
      Article and Section headings herein are for convenience only and shall not
      affect the construction hereof.




Section
      5.03. *Successors
      and Assigns* .
      All
      covenants and agreements contained in this Fourth Supplemental Indenture made
      by
      the Company shall bind its successors and assigns, whether so expressed or
      not.




Section
      5.04. *Separability
      Clause* .
      In case
      any provision in this Fourth Supplemental Indenture or in the Securities shall
      be invalid, illegal or unenforceable, the validity, legality and enforceability
      of the remaining provisions shall not in any way be affected or impaired
      thereby.




Section
      5.05. *Benefits
      of Fourth Supplemental Indenture* .
      Nothing
      in this Fourth Supplemental Indenture or in the Securities, express or implied,
      shall give to any person, other than the parties hereto and their successors
      hereunder and the Holders of the Securities, any benefit or any legal or
      equitable right, remedy or claim under this Fourth Supplemental
      Indenture.




Section
      5.06. *Execution
      and Counterparts* .
      This
      Fourth Supplemental Indenture may be executed in any number of counterparts,
      each of which shall be deemed to be an original, but all such counterparts
      shall
      together constitute but one and the same instrument.






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Section
      5.07. *Trustee
      Not Responsible for Recitals* .
      The
      recitals herein contained are made by the Company and not by the Trustee, and
      the Trustee assumes no responsibility for the correctness thereof. The Trustee
      makes no representation as to the validity or sufficiency of this Fourth
      Supplemental Indenture or of the Securities. The Trustee shall not be
      accountable for the use or application by the Company of the Securities or
      the
      proceeds thereof.




**[** SIGNATURE
      PAGE FOLLOWS **]**









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IN
      WITNESS WHEREOF, the parties hereof have caused this Fourth Supplemental
      Indenture to be duly executed by their respective officers or directors duly
      authorized thereto, all as of the day and year first above written.




MIDAMERICAN
              ENERGY
              COMPANYBy:
            /s/ Brian
              K. HankelName: 
              Brian K. HankelTitle: 
Vice
              President, Treasurer and Director




THE
              BANK OF NEW
              YORK TRUST COMPANY, NA,as
              TrusteeBy:
            /s/ 
              Roxanne EllwangerName: 
              Roxanne EllwangerTitle: 
              Assistant Vice President






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