Which Great Lake has the longest shoreline?

Lake Huron has the longest shoreline of the five Great Lakes, measuring about 6,157 kilometres when its islands are included.

Its unusually long shoreline is partly explained by Georgian Bay, the North Channel, and the many islands along its northern and eastern margins. Manitoulin Island, the world’s largest freshwater island, lies in Lake Huron and further increases the lake’s island-fringed coastline.

Shoreline totals vary depending on the measurement method and whether islands, bays, and connecting channels are counted. That is why figures can differ between references. The commonly cited total for Lake Huron includes its extensive island coastline.

Lake Huron is shared by Michigan and Ontario. It is connected to Lake Michigan by the Straits of Mackinac, and the two lakes have the same water level and function hydrologically as one lake, although they are conventionally listed as separate Great Lakes.