I just keep my home-printed maps sealed in a gallon ziplock bag. Lots lighter than laminating or that stupid heavy, almost unfoldable waterproof paper (like the almost useless Earthwalk Press maps of the Wind Rivers). If you have to move a new map to the top top, do the unsealing in your tent or with your rain jacket spread out over both your head and the maps. I've seen some map sealer stuff you can paint on maps, but I prefer plain paper plus plastic bag. The package folds up more compactly and I can write on the maps in case of need.

I have the National Geographic TOPO software for WA and OR and last spring ended up buying the Wyoming set on sale.