Hartman Reserve N. Unit is a 308. 9-acre nature reserve in Cedar Falls offering water trail access to the Cedar River and multiple lakes within the reserve as part of the Cedar Valley Paddlers' Trail, a 10-mile paddling route with portages.

The reserve features over 6 miles of walking trails (including the American Discovery Trail), an interpretive center, and facilities open daily from sunrise to sunset, making it ideal for both paddlers and hikers exploring the Cedar River ecosystem.