If you have a droid by any chance, download the $13 dollar Navionics app…I was absolutely amazed. Justin downloaded it before our trip to Mille Lacs last week. Before we found that we were concerned as we did not have a gps. That thing was every bit as good as a gps with the lakemaster chip. I held it in my hand, drove right to the contours we were interested in, drilled, and it was spot on. It has some great maps of pool 8, 7, and a couple other pools including pool 4 and lake pepin..basically, it has all the maps that you would find on the navionics north chip. Otherwise I have not found many maps of the river that I like. The bathymetry maps are the best I’ve seen.