none of the rivers form the southern border of Indiana, but the Ohio river forms the southern border of Ohio.
The Ohio River
Ohio River
The Ohio River formed the southern border of the Northwest Territory.
The border is the Ohio River.
The Ohio River.
wabash
The Ohio River and Ohio River Valley boarder the southern part of Ohio.
Ohio River
The southern border of Indiana is the OHIO River (which separates it from Kentucky.)
It's along the southern border, between Ohio and West Virginia/Kentucky. The southern edge of the state is defined by the river.
West Virginia, Ohio, Illinois, and Indiana form the northern border of Kentucky, along the Ohio River.