[1] The central interior plateau of British Columbia drained by the Fraser and Okanagan rivers is part of the Shuswap terrane in British Columbia and northern Washington state.

It is dissected by numerous elongated, glacially-overdeepened lake basins which are formed by the same mechanisms as coastal fjords.

In addition to these rivers, numerous creeks feed the lake, including Scotch Creek, which runs south to the north shore of the main arm, near the community of the same name.

Shuswap Lake is home to at least fourteen species of fish.

Eurasian water milfoil has spread across much of the lake, but is most prevalent in Salmon Arm Bay.