There is construction on the bridge over the Iowa River just north of Oakville on CR 99. Louisa County will try to keep this bridge open as they work on it until September, but may need to close it occasionally for a day at a time. Then in September they will close the bridge for about a month. The re-route is significant, especially if you are traveling southbound, so call Louisa County ahead of time to find out the status of the bridge:
Louisa County Engineer/Road Department: 319-523-5271
One reroute option:
SB:
19(30)Turn right onto CR G62. 22.5(36)Turn right onto CR 99. 23(37)Cross Iowa River. Wapello. Route becomes Franklin St. 23.5(38)Turn left onto US 61. 30(48)Turn left onto CR H22. 37.5(60)Turn right onto CR 99. Rejoin route 0.5 mi. south of Oakville.
NB:
1(2)Turn left onto CR H22. 8.5(14)Turn right onto US 61. 15(24)Wapello. Turn right onto Franklin St./CR 99. 15.5(25)Cross Iowa River. 16(26)Turn left onto CR G62. 20(32)Turn left onto CR X61. Rejoin route 3 miles south of CR G56.
CAUTION: US 61 can have high traffic and has no shoulder. Use caution.
To avoid US 61 you can ride through Illinois instead of Iowa. However, the closest to Oakville that you can cross the Mississippi river is Muscatine from the north and Burlington from the south.
See the Illinois bicycle maps for routing on the Illinois side of the river:
http://www.dot.state.il.us/bikemap/state3.html