According to the following it is now legal to carry in IN State Parks...
The Indiana Law Blog: Ind. Law - DNR lifts ban on handguns in state parks
and
Indiana restores gun carry right in state parks | Guns Magazine | Find Articles at BNET
According to this it is not, SUMMARY OF RULES AND REGULATIONS
2. Any firearm, BB gun, air gun, CO2 gun, bow and arrow, or spear gun in possession in a state park must be unloaded or un-nocked and stored in a case or locked within a vehicle except when participating in an activity authorized by written permit.
Hiking Trails in Brown County State Park - Southern Indiana Hiking Trails
The Indiana Law Blog: Ind. Law - DNR lifts ban on handguns in state parks
and
Indiana restores gun carry right in state parks | Guns Magazine | Find Articles at BNET
According to this it is not, SUMMARY OF RULES AND REGULATIONS
2. Any firearm, BB gun, air gun, CO2 gun, bow and arrow, or spear gun in possession in a state park must be unloaded or un-nocked and stored in a case or locked within a vehicle except when participating in an activity authorized by written permit.
Hiking Trails in Brown County State Park - Southern Indiana Hiking Trails