Access East-West Wacker Drive which runs parallel to the Chicago Riverwalk. Be sure you use Upper Wacker Drive and not Lower Wacker. There are multiple private garages for parking vehicles in the area around the Riverwalk. There is no official parking garage for the Chicago Riverwalk.
On the east end of the park, there is street parking on Lowest Wacker Drive between Lowest Michigan Avenue and Field Drive. Wacker Drive has free street parking on Sundays.