Iowa State Route 9 is the main east-west highway across Lyon County. It is located in the northern portion of the county. This runs from the South Dakota/Iowa State Line to the Lyon/Osceola County Line. IA St Rt 9 passes through the following towns in Lyons County. Larchwood Rock Rapids IA St Rt 9 is multi-plexed in Lyons County. U.S. Rt. 75, at Rock Rapids.
IA St Rt 9 intersects the following highways in Lyons County. Iowa State Route 182, near Larchwood.
EB IA St Rt 9 at the Iowa/South Dakota State Line. A guide marker in Larchwood. EB IA St Rt 9 south of Larchwood. EB IA St Rt 9 near Lester. EB IA St Rt 9 in Downtown Rock Rapids. EB IA St Rt 9 near Edna. WB IA St Rt 9 at the Lyons/Osceola County Line.
