Nearly 2 billion acres of offshore public domain is owned by the United States adjacent to Alaska and the lower 48 States. Much of the Nation's future domestic petroleum supply is expected to come from this area. Areas of highest potential apparently occur in deep water and in the Arctic where operating conditions are severe, development costs high, and financial risks immense. As the pace of exploration increases in these "frontier" regions, questions arise about the technologies needed to safely and efficiently explore and develop oil and gas in harsh environments. The Office of Technology Assessment undertook this assessment at the join request of the House Committees on Interior and Insular Affairs and on Merchant Marine and Fisheries. The study explores the range of technologies required for exploration and development of offshore energy resources and assesses associated economic factors and financial risks. It also evaluates the environmental factors related to energy activities in frontier regions and considers important government regulatory and service programs.