Hi Bob. You can find bathmetric or depth charts at a variety of places including local tourism ass. ...
The Sioux Lookout Travel Info. center at 807-737-2991 tells me that there are two charts available. One is coloured and covers a larger area (as far north as Route River) and the other is a line drawing showing depth contours. For both maps the above number is the best source.
For other Canadian lakes try ...
The Canadian Hydrographic service website is at
http://www.chshq.dfo.ca/ . They can also be reached by calling 1-613-998-4931
Enjoy!
Dan Good Canada's Virtual North