| Ludlow Formation | |
| Type: | Formation |
| Age: | Paleogene |
| Period: | Paleogene |
| Region: | North Dakota, South Dakota |
| Country: | United States |
| Unitof: | (partially) Fort Union Formation |
| Underlies: | Cannonball Formation and Slope Formation |
| Overlies: | Hell Creek Formation |
The Ludlow Formation is a geologic formation in western North Dakota.[1] It preserves fossils dating back to the Paleogene Period.