** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** THIS PROJECT ASSESSES HOW WETLAND REGULATION AFFECTS US RURAL ECONOMIC DEVELOPMENT. THE PROJECT'S FIRST COMPONENT BUILDS A MACHINE LEARNING MODEL TO PREDICT WHICH WETLANDS THE CLEAN WATER ACT REGULATES UNDER THE SUPREME COURT'S 2023 SACKETT DECISION, WHICH CREATED A NEW LANDSCAPE IN WETLAND LAW. THE PROJECT'S SECOND COMPONENT ESTIMATES THE CAUSAL IMPACT OF WETLAND REGULATION ON RURAL LAND MARKETS. IT ANALYZES IMPACTS OF WETLAND REGULATION ON LAND VALUES, DEVELOPMENT, AND TRANSACTIONS. IT FOCUSES ON VACANT PARCELS IN PRIMARILY RURAL AREAS, THOUGH USES RESIDENTIAL, COMMERCIAL, AND INDUSTRIAL LAND USES AS BENCHMARKS. THE PROJECT'S THIRD COMPONENT PROVIDES A PROOF-OF-CONCEPT INVESTIGATION OF HOW MACHINE LEARNING MODELS PREDICTING WETLAND REGULATION CAN SUPPORT AND IMPROVE THAT REGULATION. THE THIRD COMPONENT INVESTIGATES THE POTENTIAL OF DECISION SUPPORT TOOLS TO SUPPORT ENFORCEMENT AND DETECTION OF VIOLATIONS OF WETLAND REGULATION, AND DETERMINATIONS OF WHICH WETLANDS ARE JURISDICTIONAL. WE CONSIDER APPLICATIONS TO STATE AND FEDERAL WETLAND LAW. THE THREE COMPONENTS HAVE IMPORTANT IMPLICATIONS FOR ENVIRONMENTAL AND RESOURCE ECONOMICS AND FOR RURAL ECONOMIC DEVELOPMENT. NATIONAL MEDIA ASSERT THAT RECENT CLEAN WATER ACT CHANGES HAVE REMOVED REGULATION FOR OVER HALF OF US WETLANDS. WETLANDS CAN MITIGATE FLOODS, IMPROVE WATER QUALITY, AND PROVIDE OTHER IMPORTANT ECOSYSTEM SERVICES, AND THUS RECENT CHANGES IN REGULATION POTENTIALLY HAVE LARGE CONSEQUENCES FOR THE WELL-BEING OF RURAL COMMUNITIES. MANY RANCHING, FARMING, AND OTHER AGRICULTURAL ORGANIZATIONS HAVE ARGUED IN PUBLISHED REPORTS, MEDIA STORIES, AMICUS CURIAE BRIEFS AT THE SUPREME COURT, AND OTHER DOMAINS THAT WETLAND REGULATION PLAYS A CENTRAL ROLE IN RURAL ECONOMIC WELL-BEING.