Steve,
Although I have never been down in that area, I have to question the accuracy of the map you are using. Some times river connections are there, and sometimes they are not.
If you look at the area of where Blackey's Cove gets near to Lake Kanasatka there is no river marking at all connecting L.W. with L.K.; And yet many moons ago my cousin and I navigated our way up to the Rt. 25 highway and portaged the 14 foot Sears boat Scott motor across, to cruise for a few hours in Lake Kanasatkaand then return.