| View KML View WKT | United States Rivers |
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Boulder River
| States | Montana |
| Length | 66.5 miles |
| Watershed Length* | 119 miles |
| Mouth | Yellowstone River ⤏ Gulf of Mexico |
| GNIS | 780284 |
Tributaries
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| Name | Distance from Mouth (miles) | Length (miles) | Watershed Length (miles) |
|---|---|---|---|
| East Boulder River | 23 | 23 | 23 |
| West Boulder River | 20 | 30 | 30 |
* Note: Watershed is mostly rivers/streams 15+ miles in length.
Data from United States Geological Survey