Detail of Capt. Vancouver's 1792 chart showing the "supposed strait of Juan de Fuca". Source: viHistory
vihistory is a web site designed to aid in historical research of Vancouver Island, at which it succeeds admirably. You should poke around and have fun with their census data and the other worthy, if dreary, pursuits it affords the serious scholar.
One feature which is not immediately clear on first glance, perhaps deliberately as has entertainment potential, is a large selection of very high-resolution maps and images which you can download from this page. The file sizes are large, of course, but increasingly that is less of an obstacle in the past. The maps are mostly of historic Victoria, but there are some regional maps such as telegraph and lighthouse maps of British Columbia, and a couple of maps of Nanaimo. As usual, I have surfed through the maps so you don’t have to – and some of them are remarkably fun, and informative.
Northwest Coast Archaeology 