In 1908, a new high dam and hydroelectric power plant on the Wisconsin River brought dramatic changes to the Dells after many earlier attempts to harness the river with smaller dams. The Kilbourn Dam split the river into the Upper Dells and the Lower Dells, preventing large tourist steamboats from traveling the entire stretch. It also raised the river 17 feet on the Upper Dells, concealing many scenic caverns and unique rock formations once photographed by H.H. Bennett, who strongly opposed the dam's construction and died the year it was built.