EXHIBIT 3.107

                                                           STATE OF DELAWARE
                                                           SECRETARY OF STATE
                                                        DIVISION OF CORPORATIONS
                                                       FILED 03:00 PM 08/25/2000
                                                           001433108 - 3280072

                            CERTIFICATE OF FORMATION
                                       OF
                           PG INVESTMENTS TEN, L.L.C.

         The undersigned, an authorized natural person, for the purpose of
forming a limited liability company, under the provisions and subject to the
requirements of the State of Delaware (particularly Chapter 18, Title 6 of the
Delaware Code and the acts amendatory thereof and supplemental thereto, and
known, identified and referred to as the "Delaware Limited Liability Company
Act"), hereby certifies that:

         FIRST: The name of the limited liability company (hereinafter the
"limited liability company") is PG Investments Ten, L.L.C.

         SECOND: The address, of its registered office in the State of Delaware
is Corporation Trust Center, 1209 Orange Street, in the City of Wilmington,
County of New Castle. The name of its registered agent at such address is The
Corporation Trust Company.

         IN WITNESS WHEREOF, the undersigned has executed this Certificate of
Formation of PG Investments Ten, L.L.C. this 25th day of August, 2000.

                                               /s/ David F. Hannan
                                               ---------------------------------
                                               David F. Hannan
                                               Authorized Person



                                                           STATE OF DELAWARE
                                                           SECRETARY OF STATE
                                                       DIVISION OF CORPORATIONS
                                                       FILED 04:30 PM 10/18/2000
                                                           001527132 - 3280072

                            CERTIFICATE OF AMENDMENT

                                       OF

                           PG INVESTMENTS TEN, L.L.C.

         1.       The name of the limited liability company is PG INVESTMENTS
TEN, L.L.C..

         2.       The Certificate of Formation of the limited liability company
is hereby amended as follows:

                     CHANGE NAME TO PEABODY ARCHVEYOR, L.L.C.

         IN WITNESS WHEREOF, the undersigned has executed this Certificate of
Amendment of PG INVESTMENTS TEN, L.L.C. this 18(TM) day of OCTOBER, 2000.

                                 James C. Sevem
                      ------------------------------------
                      James C. Sevem, Assistant Secretary