The existing Komurhan Bridge was built over the dam reservoir prior to water storage. The aging segmental post-tensioned concrete bridge with two lanes had an active sagging problem at its mid-span. As the traffic demand increased over the years, the authorities decided to add two more lanes to have a twin two-lane road for this part of highway network. Therefore, a need was developed to build a new bridge. Unlike the existing one, the suggested crossing needed to pass 300 meters wide water body with a depth of 45 meters to avoid piers at water body. Couple of alternatives was considered to cross the deep water at conceptual design phase. The focus of this study is given to the conceptual design of a cable-stayed bridge with two towers crossing the water at the narrowest location. This option results in a curved back span at one side of the water. A three-dimensional computer model was developed to assess challenges in design. Special care is given to the design details of the cables and the superstructure. Even if one of the back spans is curved, the proposed conceptual cable-stay bridge design is satisfactory under service and earthquake loads.