| Lake Musselshell | |
|---|---|
 Map of Montana showing Lake Musselshell. | |
  Lake Musselshell | |
| Location | Petroleum, Phillips and Garfield Counties, Montana |
| Coordinates | 47°22′29″N 107°56′35″W / 47.374722°N 107.943056°W |
| Lake type | Glacial lake (former) |
| Primary inflows | Laurentide Ice Sheet |
| Primary outflows | Over the divide to the Yellowstone River or along the face of the Ice sheet. |
| Basin countries | United States |
| Max. length | about 140 miles (230 km) |
| Max. width | 40 miles (64 km) |
| Surface area | varied |
| Surface elevation | 315 m (1,033 ft) |
| References | [1] |
The basin that held Pleistocene Lake Musselshell is in the lower (north-flowing) reach of the river. It is underlain mostly by highly erodible Cretaceous Colorado shale, Montana group sandstone, siltstone and shale, and Hell Creek sandstone and shale. The bedrock is gently folded and affected by local faults and joints. There is a sequence of nine terraces and more than 100 glacial boulders. The terraces are older than the erratics as the erratics rest on the terraces.[2]
- ^ Physiography and Glacial Geology of Eastern Montana and Adjacent Areas; William C. Alden; United States Government Printing Office: Washington, D.C.; 1932
- ^ Extent and Timing of Laurentide Glacial Lake Musselshell, Central Montana; Nicole Kristina Davis; Montana State University; Bozeman, Montana; July 2004