Monongahela Formation

Monongahela Formation, also Monongahela Group
Stratigraphic range: Upper Pennsylvanian Gzhelian ~
File:Meigs Creek Coal (Upper Pennsylvanian; Route 7 roadcut north of Narrows Run, Belmont County, Ohio, USA) 2.jpg Coal from the Monongahela Formation
Type	Group in Ohio, Pennsylvania, parts of West Virginia and Maryland, sometimes also seen as Formation
Sub-units	Uniontown Formation Waynesburg Coal (No 11. Coal) Gilboy Sandstone Member Little Waynesburg Coal Waynesburg Limestone Member Uniontown Sandstone Member Annabelle Shale Member Uniontown Coal (No. 10 Coal) Uniontown Limestone Member "Great Lime" Fulton Shale Member Pittsburgh Formation Benwood Limestone Member Upper Sewickley Coal Upper Sewickley Sandstone Member Sewickley (Meigis Creek) Coal (No. 9 Coal) Lower Sewickley Sanstone Member Sewickley Limestone Member Cedarville Sanstone Member Redstone-Pomeroy coal (No 8a. Coal) Westone Sanstone Member Pittsburgh coal seam (No 8. Coal)
Underlies	Washington Formation
Overlies	Conemaugh Group
Location
Region	West Virginia, Pennsylvania, Ohio, Maryland
Country	United States

The Monongahela Formation is a geologic formation in West Virginia, Pennsylvania, Ohio, and Maryland. It is dated to the Carboniferous period. The top of the group is marked by the Waynesburg Coal (No. 11 Coal) and its base is marked by the Pittsburgh coal seam (No. 8 Coal). The Pittsburgh coal is the thickest and most extensive (11,000 sq mi) bituminous coal bed in the Appalachian Basin