This ecoregion incorporates the eastern slopes of the Vancouver Island Ranges and adjacent Nanaimo Lowland plain. The ecoregion contains low relief and undulating topography mixed with areas of sharp crests and narrow valleys. The climate is marked by warm, dry summers and wet, very mild winters. Frosts are common in winter, but snow cover at sea level is ephemeral. The mean annual temperature for the ecoregion is one of the mildest in Canada at approximately 9°C with a summer mean of 14°C and a winter mean of 3.5°C. Mean annual precipitation ranges from 800 mm at lower elevations to 2500 mm at higher elevations. Forest cover is characterized by stands of Douglas-fir, western hemlock and grand fir with an understory of salal, Oregon grape, and moss. Mixed stands of Douglas-fir and western hemlock with occasional Garry oak, dogwood, and arbutus are common in the driest portions of the ecoregion along the southeast coast of Vancouver Island. Higher elevation forests are composed of amabilis fir and western hemlock. Brunisolic and Podzolic soils formed on glacial drift and glaciomarine deposits dominate the ecoregion. Characteristic wildlife includes black-tailed deer, American elk (wapiti), wolf, black bear, raccoon, otter, shorebirds, seabirds, and waterfowl. Most of the mountainous portions of the ecoregion are managed for forest production under various forms of public and private tenure. On the gentler terrain adjacent to the Strait of Georgia, land use is more intensive. Residential, industrial, recreational, transportation (corridors) and agricultural uses all compete for land. There are approximately 40 000 ha of farmland mainly in the Nanaimo Lowland. Tourism and fishing are also important economic activities. Some major communities are Port Alberni, Victoria, Campbell River, and Nanaimo. The population of the ecoregion is approximately 547 600.
This ecoregion is part of the Pacific Maritime ecozone.