A state alternate route crosses the Des Moines River from Missouri into Keokuk, following US 136 into downtown. It follows a convoluted alignment, turning southeast on Main Street (still US 136), northeast on 4th Street, northwest on Orleans Avenue, northeast on 7th Street, northwest on Grand Avenue, and northeast on Rand Park Terrace, curving northwest onto the river-hugging Mississippi River Road (CR X28 and CR X21) through Montrose to US 61. US 61 and US 61 Business lead through Fort Madison to the Fort Madison Bridge and the entrance of the National Route into Iowa.