The Government of Canada's Toporama mapping site is a handy resource for trip planning. It lets you view the topographic maps for anywhere in Canada. https://atlas.gc.ca/toporama/en/index.html
This link should take you right to the Weaver River, for example: Weaver River Map (Forbes Lake to Weaver Lake section).
You can select and print off your map areas, which is nice. There are also measurement tools.