Indiana State Route 47 is a east-west highway across Northern Boone County. IN St Rt 47 passes through the following towns in Boone County. Thorntown Pike Elizaville IN St Rt 47 is not multi-plexed in Boone County. IN St Rt 47 intersects the following highways in Boone County. Indiana State Route 75, near Thorntown. U.S. Rt. 52, near Thorntown. Interstate 65, near Pike. Indiana State Route 39, at Pike. U.S. Rt. 421, near Elizaville.