2024 33 USC 9 – Des Moines River as toll free

2023 33 USC 9 – Des Moines River as toll free

2022 33 USC 9 – Des Moines River as toll free

2021 33 USC 9 – Des Moines River as toll free

2020 33 USC 9 – Des Moines River as toll free

2018 33 USC 9 – Des Moines River as toll free

2017 33 USC 9 – Des Moines River as toll free

2015 33 USC 9 – Des Moines River as toll free

2014 33 USC 9 – Des Moines River as toll free

2013 33 USC 9 – Des Moines River as toll free

2012 33 USC 9 – Des Moines River as toll free

2010 33 USC 9 – Des Moines River as toll free