Driftless Iowa, Iowa
The Upper Iowa, the Yellow River country and the climbs out of the Mississippi. 23 roads, 900 miles and 1,249 corners across Allamakee, Winneshiek, Howard, northern Clayton, Fayette counties — the northeast corner of the state, where the last glaciation stopped and left the rivers to cut the hills instead of ice flattening them.
Each road below is scored on the same five-point curviness scale, measured from the road geometry rather than guessed at: CS-1 is a road that mostly goes straight, CS-5 turns almost continuously.
| Route | Miles | Curviness | Corners | Climb ft | Shape |
|---|---|---|---|---|---|
| Yellow River Country Allamakee | 63.3 | CS-3 | 92 | 3,214 | Loop |
| Lansing Ridge Run Allamakee | 56.6 | CS-3 | 87 | 2,560 | Loop |
| McGregor and the Southern Coulees Clayton / Allamakee | 54.2 | CS-2 | 69 | 1,825 | Loop |
| Eldorado and Ossian Winneshiek | 51.2 | CS-2 | 60 | 1,877 | Loop |
| Upper Iowa Bluffs Winneshiek | 48.4 | CS-4 | 79 | 2,202 | Loop |
| Protivin and the Czech Ridges Winneshiek / Howard | 47.1 | CS-2 | 48 | 1,248 | Loop |
| Burr Oak and Hesper Winneshiek | 45.0 | CS-3 | 60 | 1,644 | Loop |
| Rossville Coulees Allamakee | 43.6 | CS-2 | 48 | 1,551 | Loop |
| Postville and the Yellow River Allamakee / Clayton | 41.9 | CS-2 | 49 | 1,523 | Loop |
| Yellow River and the Volney Coulees Allamakee | 40.9 | CS-4 | 77 | 2,621 | Point-to-point |
| Great River Road: New Albin to McGregor Allamakee / Clayton | 39.2 | CS-2 | 42 | 2,392 | Point-to-point |
| Village Creek and the Yellow River Allamakee | 39.2 | CS-3 | 57 | 2,397 | Loop |
| Cresco to Decorah the Long Way Howard / Winneshiek | 38.7 | CS-4 | 66 | 1,879 | Point-to-point |
| Czech Corner Winneshiek / Howard | 38.6 | CS-3 | 53 | 1,625 | Loop |
| Dorchester and the Northern Ridges Allamakee | 38.2 | CS-5 | 74 | 1,976 | Loop |
| Turkey River Run Winneshiek / Fayette | 34.9 | CS-2 | 40 | 1,098 | Loop |
| Lansing and the Waterville Coulees Allamakee | 33.2 | CS-2 | 42 | 1,686 | Loop |
| Volney and the Turkey River Breaks Clayton / Allamakee | 29.8 | CS-3 | 41 | 1,079 | Loop |
| Decorah to Waukon the High Way Winneshiek / Allamakee | 28.0 | CS-3 | 44 | 1,344 | Point-to-point |
| Springwater and the Upper Iowa Winneshiek | 27.8 | CS-4 | 46 | 1,468 | Loop |
| Waukon to Decorah Backroads Allamakee / Winneshiek | 22.3 | CS-2 | 28 | 641 | Point-to-point |
| Monona to Marquette Clayton | 21.0 | CS-3 | 30 | 935 | Loop |
| Mississippi Overlooks: McGregor to Harpers Ferry Clayton / Allamakee | 16.5 | CS-2 | 17 | 1,094 | Point-to-point |