Buttle Lake lies at the head of the Campbell River system which drains an area of 1,404 km2 in the central part of Vancouver Island. The drainage basin is located in the Coastal Mountains region of recently glaciated intrusive rocks and has a maritime climate. Buttle Lake lies within the coastal western hemlock zone characterized by Douglas fir, western hemlock and western red cedar.

Buttle Lake has a typical elevation of 218 m and is oriented in a north-south direction. It connects by a narrow passage to Upper Campbell Lake which feeds Lower Campbell Lake and in turn John Hart Lake and the Campbell River which flows to the sea 20 km away.

Buttle Lake is a long narrow lake and sits within a 'U-shaped' valley typical of the region having steep rock walls and a broad flat floor of unconsolidated glacial deposit. Surrounded on both sides by extensive mountain systems, the valley floor consists of many irregular knolls, depressions and long meandering gravel ridges characteristic of recently glaciated areas.

It is an ultra-oligotrophic soft water lake. Since the lake and much of its watershed have been within a provincial park since 1911, the watershed has been largely undisturbed except for forest fires until dam construction in 1958 and mine construction in 1966.

In 1958 the Strathcona Dam (power generation for B. C. Hydro) raised the levels of Upper Campbell and Buttle Lakes by 8.5 m while regulating the water level which now fluctuates some 9.0 m annually. Except during maximum reservoir draw-down, the two lakes usually have a common elevation. Approximately 8 km from its southern end occurs a sill of some 40 m depth which defines a well defined basin somewhat isolated from the remainder of Buttle Lake. In 1966 a copper-lead-zinc mine began operation near the southern end of the lake. Mine tailings from the mill were deposited directly into the south basin till 1984; additionally, acid mine generation in the drainage basin had released metals, especially copper, zinc and cadmium, which contaminated the lake via Myra Creek which discharges to the same basin. In 1983 a surface and groundwater collection and treatment system was installed at the mine site and in 1984 an on-land tailings disposal system replaced the lake disposal. These remedial measures have greatly reduced concentration of toxic metals in the lake and biological communities have returned to their former abundance (Q).