26 bridges with vertical clearance data on US-18 in Iowa. Lowest: 146.7ft.
| Clearance | Carries | Crosses | Location | Built | Map |
|---|---|---|---|---|---|
| 146.7ft | Us 18 Eb | Shellrock Rvr Redball Rd | 1.5 Mi. E Of Sr S70 | 1999 | Map |
| 150.9ft | Us 18 Wb | Winnebago River & Road | 0.7 Mi. E Of Jct. Sr S56 | 1998 | Map |
| 151.6ft | Us 18 Wb | Shellrock Rvr Redball Rd | 1.5 Mi. E Of S.R. S70 | 1999 | Map |
| 152.6ft | Us 18 Eb | Winnebago River & Road | 0.6 Mi. E Of Jct. Sr S56 | 1998 | Map |
| 162.4ft | Us 218 Sb | Ia 14 & Sherman Creek | At Jct. Ia 14 | 1999 | Map |
| 164.0ft | Us 18 Eb | I-35 | At The Jct. Of I-35 | 1998 | Map |
| 166.7ft | Us 18 Eb | Co Rd B35 | 2.4 Mi. E Of W Jct Us 218 | 1998 | Map |
| 167.7ft | Us 218 Nb | Ia 14 & Sherman Creek | At Jct. Ia 14 | 1999 | Map |
| 169.3ft | Us 18 Eb Ia 27 Sb | Us 218 T44 | Us 218 Intersection | 2022 | Map |
| 169.9ft | Us 18 Wb Ia 27 Nb | Us 218 Sb T44 | Us 218 Intersection | 2023 | Map |
| 174.9ft | Us 18 & Ia 346 | U.S. 63 | At E Jct. U.S. 63 | 2002 | Map |
| 180.1ft | Us 18 Wb | Sr B35 | 2.4 Mi. E Of W Jct Us 218 | 1998 | Map |
| 223.4ft | Us 18 | Bloody Run & Dme Rr | 1.3 Mi. W Of Jct. Ia. 76 | 1988 | Map |
| 229.3ft | Us 18 Wb & 63 Nb | Imrr And B-57 | 0.6 Mi. E Of W Jct. Us 63 | 2002 | Map |
| 230.0ft | Us 18 Wb Ia 27 Nb | Up Rr | 1.5 Mi. W Of Us 65 | 1997 | Map |
| 231.0ft | Eb Us 18 | Uprr | 0.7 Mi. E Of Jct. Us 65 | 1999 | Map |
| 231.6ft | Us 18 Eb & 63 Sb | Imrr & B-57 | 0.6 Mi. E Of W Jct. Us 63 | 2002 | Map |
| 232.6ft | Us 18 Eb | I&M Rr | 0.4 Mi. E Of Jct. Sr B35 | 1999 | Map |
| 233.3ft | Us 18 Eb Ia 27 Sb | Uprr | 1.5 Mi. W Of Us 65 | 1997 | Map |
| 233.3ft | Us 18 Wb | Ia Northern Rr & Stream | 1.1 Mi. E Of Jct Sr S70 | 1998 | Map |
| 236.5ft | Us 18 Eb | Cprr | 1.0 Mi. E Of Sr T26 | 1998 | Map |
| 241.8ft | Us 18 Wb | Uprr | 0.7 Mi. E Of Jct. U.S. 65 | 1999 | Map |
| 243.4ft | Us 18 Eb | Ia Northern Rr & Stream | 1.1 Mi. E Of Jct. Sr S70 | 1998 | Map |
| 244.1ft | Us 18 Wb | Cprr | 1.0 Mi. E Of Sr T26 | 1998 | Map |
| 251.0ft | Us 18 Wb | I&M Rr | 0.4 Mi. E Of Jct. Sr B35 | 1998 | Map |
| 285.1ft | Us 18 | Mississippi River Ia 76 | In Marquette | 1974 | Map |