Arch Lake is a lake in Carbon County, Montana, in the United States.[2]
| Arch Lake (Montana) | |
|---|---|
  Arch Lake (Montana)  Arch Lake (Montana) | |
| Location | 12 miles (19 km) northeast of US 212 |
| Coordinates | 45°09′33″N 109°44′18″W / 45.1592°N 109.7383°W |
| Lake type | natural freshwater lake |
| Basin countries | United States |
| Max. length | 2,590 ft (790 m) |
| Max. width | 930 ft (280 m) |
| Surface area | 50.24 acres (20 ha) |
| Average depth | 39 ft (12 m) |
| Max. depth | 112 ft (34 m) |
| Surface elevation | 9,997 ft (3,047 m)[1] |
| Islands | multiple islets |
Arch Lake took its name from the granite arch that sits on the south ridge.[3] It is remote from all roads, but can be reached on foot. Much of the route to it is rugged and part of the way has no trail.[4]