EXHIBIT 21.1
 
  Clark Refining & Marketing, Inc., a Delaware corporation, is registered to
do business in the following states:
 
    Delaware
    Kentucky
    South Dakota
    North Dakota
    Arkansas
    Nebraska
    Oklahoma
    West Virginia
    Indiana
    Kansas
    Mississippi
    Wisconsin
    Illinois
    Pennsylvania
    Tennessee
    Minnesota
    Michigan
    Louisiana
    Ohio
    New York
    Texas
    Missouri