 Mid-lake between the Silver River and Twenty-Mile Bay is the northern end of the lake's longest and largest island, aptly named Long Island, 9.5 km long, 2.6 km wide.The other main island of any size in the lake is Echo Island, 4 km long and 2.2 km wide.It is offshore from Harrison Hot Springs, and is immediately east of the forested canyon of the Harrison River at the lake's outflow.