Exhibit 21.1 American Midstream Partners, LP Subsidiaries As of December 31, 2018 Name Jurisdiction of Organization AMID Crude Oil Services LLC Delaware AMID Crude Oil Storage LLC Oklahoma AMID Crude Trucking LLC Delaware AMID Energy Products Supply LLC Delaware AMID Liquids Trucking LLC Delaware AMID Merger LP Delaware AMID Payment Services LLC Delaware AMID Silver Dollar Pipeline LLC Delaware AMID St. Croix LLC Delaware AMID Trans‐Union GP LLC Delaware American Midstream, LLC Delaware American Midstream AMPAN, LLC Delaware American Midstream (Alabama Gathering), LLC Alabama American Midstream (Alabama Intrastate), LLC Delaware American Midstream (AlaTenn), LLC Alabama American Midstream Bakken, LLC Delaware American Midstream (Bamagas Intrastate), LLC Delaware American Midstream Blackwater, LLC Delaware American Midstream (Burns Point), LLC Delaware American Midstream Chatom, LLC Delaware American Midstream Chatom Unit 1, LLC Delaware American Midstream Chatom Unite 2, LLC Delaware American Midstream Costar, LLC Delaware American Midstream Delta House, LLC Delaware American Midstream Emerald, LLC Delaware American Midstream East Texas Rail, LLC Delaware American Midstream EnerTrade, LLC Delaware American Midstream Finance Corporation, LLC Delaware American Midstream Gas Solutions GP, LLC Delaware American Midstream Gas Solutions LP, LLC Delaware American Midstream Gas Solutions, LP Delaware American Midstream (Lavaca), LLC Delaware American Midstream (Louisiana Intrastate), LLC Delaware American Midstream Madison, LLC Delaware American Midstream Marketing, LLC Delaware American Midstream Mesquite, LLC Delaware American Midstream (Midla), LLC Delaware American Midstream Midla Financing Holding, LLC Delaware American Midla Financing, LLC Delaware
Exhibit 21.1 American Midstream Midla Reconfiguration, LLC Delaware American Midstream (Mississippi), LLC Delaware American Midstream Offshore (Seacrest), LP Texas American Midstream Permian, LLC Delaware American Midstream Piney Woods, LLC Delaware American Midstream Republic, LLC Delaware American Midstream (SIGCO Intrastate), LLC Delaware American Midstream (Tennessee River), LLC Alabama American Midstream Transtar Gas Processing, LLC Delaware American Midstream Onshore Pipelines, LLC Delaware American Panther, LLC Delaware Argo Merger GP Sub, LLC Delaware Blackwater Investments, Inc. Delaware Blackwater Maryland, LLC Maryland Cayenne Pipeline, LLC Delaware Centana Gathering, LLC Delaware Centana Oil Gathering, LLC Delaware Cherokee Merger Sub Delaware High Point Gas Gathering, L.L.C. Texas High Point Gas Gathering Holdings, LLC Delaware High Point Gas Transmission, LLC Delaware High Point Gas Transmission Holdings, LLC Delaware Main Pass Oil Gathering Company, LLC Delaware Mid Louisiana Gas Transmission, LLC Delaware Pam Acquisition Company LLC Delaware Panther Pipeline, LLC Texas Panther Operating Company, LLC Texas Panther Offshore Gathering System, LLC Texas Trans‐Union Interstate Pipeline L. P. Delaware