I've been meaning too but keep getting distracted, I live in Northern Wisconsin.
One of the fire towers is in the Menominee Nation real far from the rest of their towns. The forest on their land is wonderfully dense but it's unclear if that towers open to the public like the other one is since they genuinely used it until 2015, and its unclear if they still use it or not with their tribal fire department. It's name is the Kinepowey Fire Lookout Tower.
The other towers more well known and less ambiguous, its just a matter of covid and if a particularly violent storm last year damaged anything.
It's the Mountain Fire Lookout Tower.
Both towers were made by the civilian conservation corp back in the 30s, and are for as i said, spotting fires due to the forest density of the region.
The one near Mountain is a park and closer to its town, the Kinepowey tower is in the heart of the Memominee Nation faraway from any towns. Trees as far as the eye can see.
I love towers but I've been cursed by a fear of heights lol, but I would love to visit the Kinepowey Tower if the tribe allows visitors, it's just a matter of being brave and getting up.