SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                         ----------------------------

                                    FORM 8-K

                                 CURRENT REPORT

                     Pursuant to Section 13 or 15(d) of the
                         Securities Exchange Act of 1934


Date of Report (Date of earliest event reported): March 11, 2004
                                                          (March 11, 2004)

                                 Arch Coal, Inc.
             (Exact name of registrant as specified in its charter)

           Delaware                       1-13105                    43-0921172
----------------------------     ---------------------------         ----------
(State or other jurisdiction      (Commission File Number)      (I.R.S. Employer
    of incorporation)                                        Identification No.)


            One CityPlace Drive, Suite 300, St. Louis, Missouri 63141
               (Address of principal executive offices) (Zip code)


          Registrant's telephone number, including area code: (314) 994-2700











                               Page 1 of 4 pages.
                         Exhibit Index begins on page 4.





Item 5. Other  Events.

     On March 11, 2004,  Arch Coal,  Inc. (the  "Company"),  announced via press
release  that it has agreed to sell 2.6 million of its 2.9 million  common units
in Natural Resource Partners for $100 million. The units will be acquired by NRP
in a private placement.


Item 7.  Exhibits.

     (c) The following Exhibit is filed with this Current Report on Form 8-K:


           Exhibit No.             Description
             99                    Press Release dated as of March 11, 2004


























                               Page 2 of 4 pages.
                         Exhibit Index begins on page 4.






                                   SIGNATURES

     Pursuant to the  requirements  of the Securities  Exchange Act of 1934, the
registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned hereunto duly authorized.

Dated:  March 11, 2004                      ARCH COAL, INC.



                                        By:   /s/ Robert G. Jones
                                          -------------------------------------
                                           Robert G. Jones
                                           Vice President - Law, General Counsel
                                               and Secretary



























                               Page 3 of 4 pages.
                         Exhibit Index begins on page 4.








                                  EXHIBIT INDEX


Exhibit No.                 Description
-----------                ------------
99                         Press Release dated as of March 11, 2004


































                                    Page 4 of 4 pages.





                                                                      Exhibit 99
News from
Arch Coal, Inc.
--------------------------------------------------------------------------------
                                                        FOR FURTHER INFORMATION:
                                                   Deck S. Slone, Vice President
                                                   Investor and Public Relations
                                                                  (314) 994-2717

                                                           FOR IMMEDIATE RELEASE
                                                         Thursday, March 11,2004

       Arch Coal Sells Units of Natural Resource Partners for $100 Million

     ST. LOUIS - Arch Coal,  Inc. today announced that it has agreed to sell 2.6
million of its 2.9 million common units in Natural Resource Partners  (NYSE:NRP)
for $100 million. The units will be acquired by NRP in a private placement.

     "This  transaction  nearly  completes a  multi-phased  effort to unlock the
value of  certain  non-strategic  assets  that had been  undervalued  on  Arch's
balance  sheet," said Steven F. Leer,  Arch's  president and CEO.  "Through this
effort that began 18 months ago, we believe we have created tremendous value for
our shareholders, while greatly enhancing Arch's financial flexibility in a very
dynamic market environment."

     With the completion of the  transaction,  Arch now has cash on hand of more
than $325 million.

     At the time of Natural Resource  Partners'  formation in October 2002, Arch
contributed  assets to NRP that were valued at $85 million on its balance  sheet
in  exchange  for an equity  ownership  position  in the  company.  Through  the
offering  of units  at the  time of the  initial  public  offering,  the sale of
subordinated  units in  December  2003 and the sale of  common  units  described
above, Arch has realized total proceeds of nearly $250 million.

     In the first  quarter,  Arch  expects to recognize a pre-tax gain of nearly
$82 million on the sale of its 2.6 million common units.

     Natural Resource Partners L.P. is headquartered in Houston, Texas, with its
operations headquarters in Huntington, W.Va. NRP is a master limited partnership
that is  principally  engaged  in the  business  of  owning  and  managing  coal
properties  in the three  major coal  producing  regions  of the United  States:
Appalachia, the Illinois Basin and the Powder River Basin.

     Arch Coal  (NYSE:ACI) is the nation's  second largest coal  producer,  with
subsidiary operations in West Virginia,  Kentucky,  Virginia,  Wyoming, Colorado
and  Utah.   Through  these   operations,   Arch  Coal  provides  the  fuel  for
approximately 6% of the electricity generated in the United States.

                                      # # #

Forward-Looking  Statements:  Statements  in this  press  release  which are not
statements of historical fact are  forward-looking  statements  within the "safe
harbor" provision of the Private Securities Litigation Reform Act of 1995. These
forward-looking  statements are based on information currently available to, and
expectations and assumptions  deemed  reasonable by, the company.  Because these
forward-looking  statements  are  subject  to various  risks and  uncertainties,
actual results may differ  materially  from those  projected in the  statements.
These  expectations,   assumptions  and  uncertainties  include:  the  company's
expectation  of  continued  growth in the demand for  electricity;  belief  that
legislation  and  regulations  relating to the Clean Air Act and the  relatively
higher costs of competing  fuels will  increase  demand for its  compliance  and
low-sulfur  coal;  expectation of continued  improved market  conditions for the
price of coal;  expectation  that the company  will  continue  to have  adequate
liquidity from its cash flow from operations, together with available borrowings
under its credit  facilities,  to finance the company's working capital needs; a
variety of operational, geologic, permitting, labor and weather related factors;
and the other risks and  uncertainties  which are described from time to time in
the company's reports filed with the Securities and Exchange Commission.