<DOCUMENT>
<TYPE>EX-21
<SEQUENCE>4
<FILENAME>d94498ex21.txt
<DESCRIPTION>LIST OF CORPORATION'S SIGNIFICANT SUBSIDIARIES
<TEXT>
<PAGE>

                                                                      EXHIBIT 21



SIGNIFICANT SUBSIDIARIES OF UNION PACIFIC CORPORATION

<Table>
<Caption>
                                                                                        State of
Name of Corporation                                                                     Incorporation
-------------------                                                                     -------------

<S>                                                                                     <C>
Union Pacific Railroad Company......................................................    Delaware
Southern Pacific Rail Corporation...................................................    Utah
Overnite Transportation Company.....................................................    Virginia
</Table>




</TEXT>
</DOCUMENT>
