ALTHOUGH A FLEXIBLE AND POWERFUL TOOL IN RECENT YEARS FOR THE LITIGATION OF ENVIRONMENTAL AND NATURAL RESOURCE ISSUES, THE PUBLIC TRUST DOCTRINE IS AN ANCIENT CONCEPT. THIS DOCUMENT FIRST EXAMINES THESE HISTORICAL ORIGINS OF THE CONCEPT, SPECIFICALLY NOTING ITS USE IN BOTH THE ROMAN LAW AND IN ENGLISH COMMON CASE LAW. THE DEVELOPMENT OF THE PUBLIC TRUST DOCTRINE IN AMERICA BEFORE 1900 IS THEN EXAMINED THROUGH A SERIES OF COURT CASES. PROCEDURAL ASPECTS OF TRUST ENFORCEMENT ARE NEXT REVIEWED, INCLUDING STATUTES AND CONSTITUTIONAL PROVISIONS CONCERNING THE PUBLIC TRUST, CAUSES OF ACTION, PARENS PATRIAE CASES, AND REMEDIES. THE APPLICATION OF THIS DOCTRINE TO RESOURCES SUCH AS WETLANDS, WATER RESOURCES, WILDLIFE, AND PUBLIC LANDS AND PARKS ARE DESCRIBED. ALSO OUTLINED ARE THE STATE'S POWERS AND LIMITS WITH REGARD TO DIVERSION OF THESE TRUST RESOURCES....DMC