I received a response from MO State Parks and I think I'm calling BS. Here’s their response to my email.
"Thank you for contacting us.
I appreciate your concern and sending the photographs of the tree. Unfortunately, that tree is currently protected due to it also being a roosting tree for bats and we are under strict guidelines for not cutting any roost trees during the season. Because of this, park staff have blocked the road under the remaining living branch to prevent drivers from potentially damaging personal property. Once the last branch of the tree has died, staff will re-evaluate the situation to determine if the tree can be removed.
Jenn Wood
Missouri State Parks"
While I know bats can and do roost in trees, WNS has wiped out most of the bats in the area of Meramec State Park. Also about 100 yards from that tree is Fisher Cave which I believe the bats would prefer for roosting.