Gamma World. The iconic map of the former USA, 2471 AD. 3rd print map, laid over the 2nd print map.
EDIT April 20, 2019
I got a 1st edition/1st print (TSR Lizard logo) set in the shop, so I took some photos comparing its map with a 2nd printing map.
At first I thought the 1st edition map’s rivers had been traced in pen by a former owner, they are so bold.
But that’s not the case. Note in the detail shot below, the rivers grow faint identically in the same places. Somebody tracing with a pen wouldn’t do that.
Other than color shifts, the maps have different copyright notices.