It ends in Lake Pepin of the Mississippi River, about 1 mile (2 km) west of the village of Maiden Rock in Pierce County.

While the land near the source is relatively flat, the river soon falls into a steep valley typical of the Driftless Area, with outcrops of sandstone and limestone.

This is because it is more of a free-stone stream than the upper Kinnickinnic, with slightly warmer water, which produces larger food sources for the trout.

The warmer water of some stretches also affects the fish species found in the river.

The last few miles of the stream holds an increasing proportion of medium-temperature riverine species, such as smallmouth bass.