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                                                                   EXHIBIT 4.206

                       LIMITED LIABILITY COMPANY AGREEMENT
                                       OF
                      WATERSIDE-MARISSA DEVELOPMENT, L.L.C.

         THIS LIMITED LIABILITY WATERSIDE-MARISSA DEVELOPMENT, L.L.C., (the
"LLC"), is dated as of January 7, 2004 and made by Peabody-Waterside
Development, LLC, a Delaware limited liability company (the "Member").


                                   WITNESSETH:

         WHEREAS, the LLC is a limited liability company formed under the
Delaware Limited Liability Company Act (the "Delaware LLC Act") pursuant to a
Certificate of Formation filed with the Delaware Secretary of State on January
7, 2004; and

         WHEREAS, the Members of the LLC form a Joint-Venture Management
Committee (the "LLC").

         NOW, THEREFORE, the Management Committee hereby declares as follows:

1. LLC FORMATION, NAME, PLACE OF BUSINESS

         1.1 FORMATION OF LLC; CERTIFICATE OF FORMATION

             The Management Committee of the LLC hereby acknowledges the
formation of the LLC as a limited liability company pursuant to the Delaware LLC
Act by virtue of the filing of a Certificate of Formation with the Delaware
Secretary of State on January 7, 2004.

         1.2 NAME OF LLC

             The name of the LLC as of the date of this Agreement is and shall
continue to be "Waterside-Marissa Development, L.L.C.". The business of the LLC
may be conducted under any other name that is permitted by the Delaware LLC Act
and selected by the Members of the Management Committee ("Committee"). The
Committee designated pursuant to the terms of this Agreement promptly shall
execute, file, and record any assumed or fictitious name certificates required
by the laws of the State of Delaware or any state in which the LLC conducts
business and shall take such other action as such Committee determines is
required by or advisable under the laws of the State of


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Delaware, or any other state in which the LLC conducts business, to use the name
or names under which the LLC conducts business.

         1.3 PLACE OF BUSINESS

             The LLC's principal place of business shall be St. Louis, Missouri.
The Committee may establish and maintain such other offices and additional
places of business of the LLC, either within or without the State of Delaware,
or close any office or place of business of the LLC, as he or she deems
appropriate.

         1.4 REGISTERED AGENT

             The street address of the initial registered office of the LLC
shall be:

                  The Corporation Trust Company
                  Corporation Trust Center
                  1209 Orange Street
                  Wilmington, Delaware  19801

and the LLC's registered agent at such address shall be Corporation Service
Company. The Manager may from time to time appoint a new resident agent for the
LLC.

2. PURPOSES AND POWERS OF LLC

         2.1 PURPOSES

             The purposes of the LLC shall be (i) to invest in, develop and/or
operate other related concerns and transactions (ii) to undertake any lawful
transactions and engage in any lawful activity incidental to or in furtherance
of the foregoing purposes or otherwise related to the energy business; and (iv)
as agreed by the Member, to engage in any other lawful business, purpose or
activity permitted by the Delaware LLC Act.

         2.2 POWERS

             The LLC shall have all the powers and privileges as are necessary
or convenient to the conduct, promotion, or attainment of the business, purposes
or activities of the LLC.



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3. TERM OF LLC

             The LLC commenced on the date upon which the Certificate of
Formation was duly filed with the Delaware Secretary of State and shall continue
until the dissolution of the LLC as provided by the Delaware LLC Act.

4. LIABILITY OF MEMBER

             Except as otherwise provided in the Delaware LLC Act, the debts,
obligations and liabilities of the LLC, whether arising in contract, tort or
otherwise, shall be solely the debts, obligations and liabilities of the LLC,
and neither the Committee, any officer, employee, shareholder, controlling
person or agent of the LLC or the Committee shall be obligated personally for
any such debt, obligation or liability of the LLC solely by reason of being a
Committee member officer, employee, shareholder, controlling person or agent of
the LLC or the Member. The failure of the LLC to observe any formalities or
requirements relating to the exercise of its power or management of its business
or affairs under the Delaware LLC Act or this Agreement shall not be grounds for
imposing personal liability on the Committee, or any, manager, officer,
employee, shareholder, controlling person or agent of the LLC or the Member for
liabilities of the LLC.

5. CAPITALIZATION, MEMBERSHIP INTEREST AND DISTRIBUTIONS OF CASH FLOW AND
   CERTAIN PROCEEDS.

         5.1 CAPITALIZATION

             Concurrent with the execution of this Agreement, the Committee
shall make a $1,000 capital contribution to the LLC, in cash.

         5.2 NO ADDITIONAL CAPITAL CONTRIBUTIONS

             The Committee shall have no obligation to make additional capital
contributions to the LLC.

         5.3 MEMBERSHIP INTEREST

             The Committee shall own one hundred percent (100%) of the
membership interests in the LLC, and all profits and losses shall be allocated
to the Members.

         5.4 DISTRIBUTIONS

             The Committee shall decide whether and in what amounts the proceeds
received by the LLC shall be distributed. All such proceeds, if any, shall be
distributed one hundred percent (100%) to the Members.


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6. MANAGEMENT

         6.1 MANAGEMENT BY MANAGER

             Management of the LLC is vested in a Management Committee and not
in the Member. The Committee shall be elected by the Member. The Committee may
exercise all such powers of the LLC and do all such lawful acts and things as
may be done by a manager of a limited liability company under the Act.

         6.2 MANAGEMENT COMMITTEE'S TERM OF OFFICE

             The Management Committee shall remain in office until they resigns
or are removed from the office by the Committee. Terry L. Bethel shall be the
initial Manager of the LLC. The Committee will devote such time and attention to
the LLC as is appropriate to manage the affairs of the LLC to its best
advantage.

         6.3 IMPLEMENTATION OF ACTIONS OF MANAGEMENT COMMITTEE

             The decisions and actions of the Committee shall be carried out by
the Committee Members or such other individuals granted authority to act on
behalf of the Committee, pursuant to decisions made or resolutions adopted from
time to time by the Committee.

7. INDEMNIFICATION OF REPRESENTATIVES, COMMITTEE MEMBERS AND EMPLOYEES

         7.1 INDEMNIFICATION

             The LLC shall indemnify and hold harmless the Committee Members,
the Manager and each officer, employee, shareholder, controlling person, agent
and representative of the LLC and of the Member (individually, in each case, an
"Indemnitee") to the fullest extent permitted by law from and against any and
all losses, claims, demands, costs, damages, liabilities (joint or several),
reasonable expenses of any nature (including reasonable attorneys' fees and
disbursements), judgments, fines, settlements, and other amounts arising from
any and all claims, causes of action, demands, actions, suits, or proceedings
(unless asserted by the LLC against the Indemnitee), whether civil, criminal,
administrative or investigative, in which the Indemnitee may be involved, or
threatened to be involved, as a party or otherwise, arising out of or incidental
to the business or activities of or relating to the LLC (a "Claim"), regardless
of whether such Indemnitee continues to be a Committee Member or Manager or an
officer, employee, shareholder, controlling person, agent or representative of
the LLC or the Member at the time any such liability or expense is paid or


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incurred, if such Indemnitee determined in good faith that such conduct was in
the best interest of the LLC and such Indemnitee's conduct did not constitute
fraud, gross negligence, or willful misconduct and was within the scope of the
Indemnitee's authority; provided that all claims for indemnification by an
Indemnitee shall be made only against and shall be limited to the assets of the
LLC and no Indemnitee shall have recourse against the Member with respect to any
such Claim. The termination of any action, suit, or proceeding by judgment,
order, settlement, or conviction, or upon a plea of nolo contendre or its
equivalent shall not, in and of itself, create a presumption or otherwise
constitute evidence that the Indemnitee's conduct did constitute fraud, gross
negligence, or willful misconduct.

         7.2 EXPENSES

             Expenses incurred by an Indemnitee in defending any Claim subject
to this SECTION 7 shall, from time to time, upon request by the Indemnitee, be
advanced by the LLC prior to the final disposition of such Claim upon receipt by
the LLC of an undertaking by or on behalf of the Indemnitee to repay such
amount, together with interest on any such advance or advances at the rate equal
to two percentage points above the "Federal short-term rate" as defined in the
Internal Revenue Code section 1274(d)(1)(C)(i) or the maximum rate permitted
under applicable law, promptly upon (and in no event more than ten days after) a
determination in a judicial proceeding or a binding arbitration that such
Indemnitee is not entitled to be indemnified as authorized in this SECTION 7.

         7.3 OTHER RIGHTS

             The indemnification provided by this SECTION 7 shall be in addition
to any other rights to which an Indemnitee may be entitled under any agreement
or as approved by the Committee, as a matter of law or equity, or otherwise,
both as to an action in such Indemnitee's capacity as the Committee or Manager,
or as an officer, employee, shareholder, controlling person, agent or
representative of the LLC or the Committee, and as to an action in another
capacity, and shall continue as to an Indemnitee who has ceased to serve in such
capacity with respect to those periods during which such Indemnitee served, and
shall inure to the benefit of the heirs, successors, assigns, and administrators
of the Indemnitee.

         7.4 NOTICE

             Promptly after receipt of notice of the commencement of any Claim,
an Indemnitee will, if indemnification in respect thereof is to be sought
against the LLC under this SECTION 7, notify the LLC of the initiation thereof,
but the omission so to notify the LLC will not relieve the LLC from any
liability


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that the LLC may have to such Indemnitee otherwise than under this SECTION 7, or
under this SECTION 7 except to the extent that the LLC is adversely affected by
such lack of notice.

         7.5 COUNSEL

             The LLC shall have the right to undertake, by counsel or other
representatives of its own choosing, the defense or other resolution of any
Claim. In the event that the LLC shall elect not to undertake such defense or
other resolution or within a reasonable time after notice of such Claim from an
Indemnitee, the LLC shall fail to defend or otherwise resolve such Claim, such
Indemnitee (upon further written notice to the LLC) shall have the right to
undertake the defense, compromise, or settlement of such Claim, by counsel or
other representatives of its own choosing, on behalf of and for the account and
risk of the LLC.

         7.6 OTHER PERSONS

             The provisions of this SECTION 7 are for the benefit of the
Indemnitees and shall not be deemed to create any rights for the benefit of any
other person or entity.

         7.7 INSURANCE

             The LLC may purchase and maintain insurance of a kind normal and
customary in the industry in which the LLC conducts business on behalf of any
Indemnitee against any liability asserted against an Indemnitee and incurred by
an Indemnitee in such capacity, or arising out of such Indemnitee's status as
aforesaid, whether or not the LLC would have the power to indemnify such
Indemnitee against such liability under this SECTION 7.

8. DISSOLUTION AND LIQUIDATION

         8.1 EFFECT OF DISSOLUTION

             Upon dissolution, the LLC shall cease carrying on its business but
shall not terminate until the winding up of the affairs of the LLC is completed,
the assets of the LLC shall have been distributed as provided below and a
Certificate of Cancellation of the LLC under the Delaware LLC Act has been filed
with the Secretary of State of the State of Delaware.


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         8.2 LIQUIDATION UPON DISSOLUTION

             Upon the dissolution of the LLC, sole and plenary authority to
effectuate the liquidation of the assets of the LLC shall be vested in the
Committee, which shall have full power and authority to sell, assign and
encumber any and all of the LLC's assets and to wind up and liquidate the
affairs of the LLC in an orderly and business-like manner. The proceeds of
liquidation of the assets of the LLC distributable upon a dissolution and
winding up of the LLC shall be applied in the following order of priority:

             (i) first, to the creditors of the LLC, which may include the
Members of the Committee as a creditor, in the order of priority provided by
law, in satisfaction of all liabilities and obligations of the LLC (or any
nature whatsoever, including, without limitation, fixed or contingent, matured
or unmatured, legal or equitable, secured or unsecured), whether by payment or
the making of reasonable provisions for payment thereof; and

             (ii) thereafter, one hundred percent (100%) to the Member.

         8.3 WINDING UP AND CERTIFICATE OF CANCELLATION

             The winding up of the LLC shall be completed when all of its debts,
liabilities, and obligations have been paid and discharged or reasonably
adequate provisions therefor has been made, and all of the remaining property
and assets of the LLC have been distributed to the Member. Upon the completion
of the winding up of the LLC, a Certificate of Cancellation of the LLC shall be
filed with the Delaware Secretary of State.

9. AMENDMENT

             This Agreement may be amended or modified by a written instrument
executed by the Member.

10. GOVERNING LAW

             This Agreement shall be governed and construed in accordance with
the laws of the State of Delaware without regard to any applicable conflicts of
law.


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             IN WITNESS WHEREOF, the undersigned has duly executed this
Agreement, as of the day and year first herein above set forth.

                        WATERSIDE-MARISSA DEVELOPMENT, L.L.C.

                              By:
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                              Name: Member Management Committee
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                              By:
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                              Name: Member Management Committee
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                              By:
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                              Name: Member Management Committee
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                              By:
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                              Name: Member Management Committee
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