32 bridges with vertical clearance data on SR-21 in Michigan. Lowest: 143.4ft.
| Clearance | Carries | Crosses | Location | Built | Map |
|---|---|---|---|---|---|
| 143.4ft | M-21 Wb | I-96 Eb Ramp | 0.2 Mi E Of Grand Rapids | 1961 | Map |
| 151.6ft | Fifth St, M-21 | I-475 & Ramps C&D | In Flint | 1970 | Map |
| 152.6ft | M-21|Corunna Rd | I-75 Nb | Near W Lts Of Flint | 2009 | Map |
| 160.1ft | Rmp B M-21Br I-196 | I-196 Eb | In Wyoming (I-196 Eb) | 1965 | Map |
| 160.8ft | M-21 Eb | I-96 & M-21 | 0.4 Mi E Of Grand Rapids | 1961 | Map |
| 161.7ft | M-21 Wb | I-96 & M-21 | 0.3 Mi E Of Grand Rapids | 1961 | Map |
| 229.3ft | M-21 | Grand Rapids Eastern Rr | 3.5 Mi W Of Ada | 1977 | Map |
| 1000.0ft | M-21 | Lost Creek | 3.5 Mi W Of Fowler | 2005 | Map |
| 1000.0ft | M-21 | North Swargart Drain | 3.2 Mi E Of Fowler | 1977 | Map |
| 1000.0ft | M-21 | Waltz & Sturgis Drain | Sorrel St In Fowler | 2005 | Map |
| 1000.0ft | M-21 | Kneeland Drain | 0.1 Mi W Of Francis Rd | 2005 | Map |
| 1000.0ft | M-21 | S Fork Of Hayworth Creek | 1.1 Mi E Of Lowell Rd | 2005 | Map |
| 1000.0ft | M-21 | Maple River | 2.0 Mi W Of Ovid | 1929 | Map |
| 1000.0ft | M-21 | Alder Creek | 1.2 Mi W Of Ovid | 1949 | Map |
| 1000.0ft | M-21 | Maple River | In Ovid | 1997 | Map |
| 1000.0ft | M-21 | Swartz Creek | In Flint | 1918 | Map |
| 1000.0ft | M-21 | Csx Rr (Abn) | In Flint | 1918 | Map |
| 1000.0ft | M-21 | Toles Creek | 2.6 Mi E Of Kent Co Line | 1929 | Map |
| 1000.0ft | M-21 | Red Creek | 6.3 Mi E Of Kent Co Line | 1929 | Map |
| 1000.0ft | M-21 | Bellany Creek | 2.3 Mi W Of Ionia | 1930 | Map |
| 1000.0ft | M-21 | Prairie Creek | 2.6 Mi E Of M-66 | 1929 | Map |
| 1000.0ft | M-21 | Maple River | 1.0 Mi E Of Muir | 1929 | Map |
| 1000.0ft | M-21 | Stoney Creek | 1.5 Mi E Of Muir | 1929 | Map |
| 1000.0ft | M-21 Br | Plaster Creek | In Wyoming | 1916 | Map |
| 1000.0ft | M-21 | Grand River | 6.4 Mi E Of I-96 | 2010 | Map |
| 1000.0ft | M-21 | Flat River | In Lowell (118 W Main St) | 1941 | Map |
| 1000.0ft | M-21 | Flat River | In Lowell (107 E Main St) | 1940 | Map |
| 1000.0ft | M-22|Main St | Leland River | In Leland | 1929 | Map |
| 1000.0ft | M-21 | Lewis Drain | 1.4 Mi E Of Clinton Col | 1998 | Map |
| 1000.0ft | M-21 | Shiawassee River | In Owosso | 1970 | Map |
| 1000.0ft | M-21 | Rush Creek | 2.8 Mi W Of Genesee Col | 2022 | Map |
| 1000.0ft | M-21 | Limbarg County Drain | 1.6 Mi W Of Genesee Col | 2009 | Map |