The former Fort William section occupies flat alluvial land along the Kaministiquia River .
Thunder Bay , which gives the city its name , is about 22.5 kilometres ( 14.0 mi ) from the Port Arthur downtown to Thunder Cape at the tip of the Sleeping Giant .
The former Port Arthur   section occupies flat alluvial land along the Kaministiquia River .
Thunder Bay , which gives the city its name , is about 22.5 kilometres ( 14.0 mi ) from the Port Arthur downtown to Thunder Cape at the tip of the Sleeping Giant .