It was designated in 2000 by UNESCO to protect a large second-growth coast Douglas fir ecosystem in the watersheds of the Little Qualicum and Englishman Rivers from being developed.

[1] The watersheds of the Little Qualicum and Englishman Rivers on the northeastern slope of Mount Arrowsmith were once home to a large old-growth forest dominated by coast Douglas fir.

In the mid-1990s, local logging industries pressured the provincial government to permit clearcutting in the area as the trees neared their harvestable size.

[1] In November 2008, the governing body of Alberni-Clayoquot Regional District in cooperation with local conservation groups established Mount Arrowsmith Massif Regional Park within the biosphere reserve to further protecting the forest from being clearcut.

[4] In 2014, VIU established the Mount Arrowsmith Biosphere Region Research Institute, which is governed by representatives from the Qualicum First Nation, Snaw-naw-as First Nation, City of Parksville, Town of Qualicum Beach, Regional District of Nanaimo, BC Ministry of Environment and Climate Change Strategy, Vancouver Island Conservation Land Management Program, Island Timberlands, TimberWest, and VIU.