11 bridges with vertical clearance data on US-421 in Kentucky. Lowest: 119.1ft.
| Clearance | Carries | Crosses | Location | Built | Map |
|---|---|---|---|---|---|
| 119.1ft | Us 421 | Ohio River | At Ky/In State Line | 2014 | Map |
| 160.1ft | Us 421 | I-71 | 1.6 Mi N Of Ky 997 | 1968 | Map |
| 165.0ft | Us-421 | Southern Rr | 1 Mi. East Of Jct Ky 4 | 2005 | Map |
| 220.1ft | Us-421 | Csx Rr-Ky 480-Clover Fk | .15 Mi S Of S-Jct Us 421 | 1974 | Map |
| 229.3ft | Us-421 | Csx Railroad | .1Mi W-Jct Us 25 N Lxngtn | 1981 | Map |
| 232.9ft | Us 421 | Csx Railroad | 150 Ft N Of Ky 574 | 2009 | Map |
| 239.8ft | Us-421 | Clover Fork & L.&N. R.R. | .4 Mi N-Clover St-Ky 38 | 1974 | Map |
| 399.9ft | Us-421 | Martins Fk Csx , Ky-3001 | Martins Fk Csx Old421 | 2004 | Map |
| 536.7ft | Us-0421 | Csx Railroad | Over Csx Railroad | 2004 | Map |
| 609.9ft | Us-421 | Ky 1556 & Bobs Creek | 8.123 Mi Nw Va.St Line | 2004 | Map |
| 700.1ft | Us-0421 | Martins Fk Cumberland R | 7.7 Mi N Of Va.State Line | 2004 | Map |