Not sure if you mean when the maps are closed or fully open but, I use CM albums and use the 8 1/2 x 11 Portrait sleeves in my 12x12 albums for report cards and notes from teachers so maybe these would work for you if you use strap hindged albums.
Did you know that CM sticker packs are also album safe. So when you are finished with the stickers you can use the pack for tickets etc.. Maybe one of their great length packs might hold a map?