The Alberni Valley straddles Highway 4 on Vancouver Island, from the east end of Cameron Lake to the western tip of Sproat Lake. It encompasses Mt Arrowsmith, Cameron Lake, Cathedral Grove, MacMillan Provincial Park, the City of Port Alberni, and Sproat Lake (including Taylor Arm Provincial Park and Fossil Provincial Park. The terrain of the area is diverse, including low-lying areas around the north end of the Alberni inlet, primeval rainforests, wild mountain regions, and Mt Arrowsmith, the highest peak (elevation 1,819 m) on Southern Vancouver Island.