From 1976-1979, Mr. Preston was Legislative Analyst and then Staff Director of the Florida Senate Natural Resources and Conservation Committee. He helped establish and then grow and develop Hopping Green & Sams, P.A., one of Florida's most capable boutique law firms in the field of administrative, governmental and environmental law. He practiced with HGS for over 20+ years before opening his own firm in 2001. He has written a number of law review articles and other publications. He frequently lectures and conducts seminars on environmental law and regulatory topics of a diverse nature for various organizations including The Florida chamber of Commerce, as well as at pat symposia on Environmental Contamination in Central and Eastern Europe, in Warsaw, Poland and Prague, Czech Republic, 1996-2000.