1952 edition
I refer to this as the black-and-white map. I’ve copied this from the Forest Service website’s towers page. My understanding is that this is from 1952 when there were 32 towers.
Some of the towers are marked as “FS” presumably meaning US Forest Service as opposed to state properties. Three towers in Martin County are marked as “N” presumably standing for Naval to refer to the naval ammunition facility at Crane.
I believe the map is saying that these were actual standing towers at the time it was made. (Unlike the colorful map, which includes non-standing ex-towers.)
This map matches the colorful map in the north, with three tower sites. I think the note at the bottom is interesting, saying that the towers in the north were not solely about fire protection.
Note that there is no tower in Morgan county, which is where the Wilbur tower was.
Note that there is no tower in Washington county, where the Salem tower is today. I read that the Borden tower originally in Clark County was moved here. So I’m guessing that this map was made before that tower was moved.
1943 edition
This map is from 1943, taken from this IDNR history of fire in Indiana. Note that only one of the three Crane towers in northern Martin County is visible. Note that the Ouabache tower is not visible in Wells County. The towers in southern Monroe and northern Jackson counties are different than in 1952.
The fire districts are also different than in the later map.
This article from Dec 1942 OI has a map that’s very similar. Here it is in detail:
