A great guide book indeed. It was out of print for awhile, but it seems it's available new via the "Boundary Waters Journal" and their website.
A Paddler's Guide to Quetico Provincial Park Although Kevin Callan's "A Paddler's Guide to Quetico and Beyond" is a better read, Beyer's Quetico guide is incredibly helpful for calculating a daily traveling itinerary. Almost a must have for a Quetico first time tripper in my opinion.
I literally wore out my 1985 copy, which was the initial year of release. Some of the information is a little dated, because Robert Beyer essentially compiled most all of the book's data during the summer of 1984. Surprisingly I didn't cross paths with Mr. Beymer, having spent 4-weeks in Quetico in the summer of 1984 myself.
Hans Solo