I went to Voyageurs National park last year, and am going again this september, I found it to be an awesome place to observe. This is located near Orr, Mn. - west of ELY
right off of hwy 53. We stayed on Lake Kabetogama, for this was the only lake in the chain that is completely in Minnesota ( easier to figure out the limits and liscenses needed). We had an awesome time, and can not wait to go again. The lakes in this Park are ( Rainy lake, Namakan, Sand Point, Crane, and Kabetogama). Our resort we stayed at ( asuming you are looking for a roof over your head for your dad?) Was Pokorny's resort http://www.pokornysresort.com/.
Their cabins are modest, but more than sufficient for a wonderful fishing trip. There are others in the area such as the red Pine lodge and resort, and the lakeview resort, and all have similar prices, all do have boat rentals I believe. they are in a perfect location because it is in the center of the large lake, lessoning the run if the fish are biting on one end of the lake or the other. If you stop by the Gateway store http://www.gatewaygeneral.com/
( which is the gas station right on hwy 53 where you turn off to go to the resorts listed) you can pick up a navionics map from them for around $30 which gives you more detail than the standard hotspots map to catch plenty of fish, I have both maps and like the navionics better.
Hope this helps, if you need more info to any of these places, you can PM me and I will try and assist.
HOpe your trip planning goes well, it is always more fun to get the old guys on a good trip. LOL