This region is characterized by an exceptionally wet and mild rainforest climate, and is part of the coastal western hemlock Biogeoclimatic Zone. Port Renfrew receives an annual average total for rainfall of 3.6 meters, or close to 12 feet per year. Overall the landscape of this region varies from seashore regions to nearly flat, featureless plains to regions of protruding and steeply sloped bluffs. The San Juan Valley, created by a geological fault, reaches 35 kms inland and is 2.5 kms at its widest point. Pacheedaht hosts one of the highest bio-mass growing forests in the world.
A myriad of lakes, rivers and streams fed by the successive mountain ranges and narrow valleys create impressive watersheds in the region. The San Juan River watershed, the major watershed of this region, has been impacted by extensive logging. The river has lost critical salmon spawning habitat, and parts of the river remain choked with debris. The San Juan River empties into Port San Juan near Port Renfrew, creating an intertidal wetland at Harris Cove beside the Pacheedaht First Nations Reserve.
This region is home to some of the world's largest spruce trees, some reaching heights in excess of 95 meters and living for 800 years or more. This large Sitka spruce ecosystem represents 2% of BC's remaining old-growth forest. Sitka spruce, tolerant of salt spray, edges the coastline. The spruce also requires a porous and moist soil, and is prevalent along the flood plains of creeks and rivers. Blanketing the upper mountainous areas, are the shade tolerant, cedar-hemlock forests.
Douglas fir sporadically covers all forest areas. A short drive north of Port Renfrew stands the Red Creek Fir, one of the largest Douglas fir trees in Canada. At present it measures over 41 feet in circumference, with a height of 241 feet, although at one time it must have been about 320 feet high before losing its spire to wind or lightning.
Botanical Beach affords visitors with access to uniquely rich tide pools and shoreline trails with fantastic geological features. The extensive variety of marine flora and fauna in this colourful intertidal zone includes red, purple and orange starfish and sea urchins, white gooseneck barnacles, blue mussels and green sea anemones and sea cucumbers. Coralline algae, periwinkles, chitons and sea stars can also be seen at Botanical Beach.
The region is so biologically significant that the University of Minnesota installed the first marine research station in the Pacific Northwest at Botanical Beach in 1901. Since then, the area has been used for research by a number of universities in BC and Washington.
With regards to marine wildlife, this region is an important area for cormorants, grebes and loons. It is a very high value killer whale habitat, and is a migratory corridor for gray, killer and minke whales.