There are two 5k routes, both are paved & nearly level. The loop trail heads south paralleling the Missouri River with a pretty view of St. Charles on the opposite bank and returns along the levee. The out-and-back trail goes north along the levee, passing under a railroad bridge and Highway 370 with a turnaround at Missouri Bottoms Trailhead. This trail has two slight inclines.
Riverwoods Park & Trail & Earth City Levee Trail brochure