It's mention worthy to note that the Cascade Volcanic Arc extends beyond the official border of the Cascade Range. According to Beckey, the northern border of the Cascade mountain range is defined by the Fraser River. Interestingly, the Cascade Volcanic Chain extends well beyond that into the Coastal Range, north of Vancouver Island. See this photo.
The Tacoma Mountaineers were not incorrect when they included Garibaldi in their Cascade Volcanoes list. This page should probably include the Garibaldi page and any other volcanic remnants in Southern BC or the name should be changed to "Volcanoes of the Cascade Range".