| Blue Mountain Stream | |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | New York |
| Mouth: | Middle Branch Grass River |
| Mouth Location: | Newbridge, New York |
| Mouth Coordinates: | 44.3575°N -74.9203°W |
| Mouth Elevation: | 1222feet |
| Basin Size Mi2: | 14.2 |
Blue Mountain Stream flows into the Middle Branch Grass River near Newbridge, New York. The Blue Mountain Stream and Pleasant Lake Stream combine here to become Middle Branch Grass River.[1]