I picked up a gps for the trip this year, got it free through work. Anyways I have been playing around some trying to dl maps to it. I found the forum that had links to different maps for free but so far only was succesful loading bw portage and campsites map, which is great but are there any better maps? The map lacks a lot of details, like topo or water depth would be awesome.

You may need to download the MN topographic map link
this page shows both the bwca map and the topo map together