The Charles Ross House, or Forest House, is a lakeside summer residence on Lake Delavan in Delavan, Wisconsin, designed by Frank Lloyd Wright in 1902. Considered one of the finest examples of his Prairie style, it marked an early and influential step in his move away from the conventional boxed house plan. Created during a period when wealthy Chicago families sought summer homes in Wisconsin, it combines features such as board-and-batten siding, hipped roofs, ribbon windows, and a broad lakeside patio with a cruciform plan that dissolves room boundaries. Its dynamic interior space anticipated the more complex arrangements of Wright’s later Prairie houses.