Iowa 173 connects Elk Horn and Kimballton, two small towns with tributes to their residents' Danish heritage.

Designated in 1930, the highway was originally a spur route into Elk Horn from Kimballton.

It heads north through rural Cass County and intersects Interstate 80 (I-80) at a partial cloverleaf interchange.

Just north of the Interstate Highway, the route enters Shelby County.

It continues north for three miles (4.8 km) until it reaches Kimballton, where it also runs along Main Street.