Dams in Sweet Grass County, Montana
18Total Dams
4High Hazard
3Significant
Dam Safety in Sweet Grass County, Montana
Sweet Grass County has 18 dams tracked in the National Inventory of Dams. Of these, 4 are classified as high hazard — meaning failure would probably cause loss of human life. Another 3 carry a significant hazard classification. Currently, 3 dams have a condition assessment of poor or unsatisfactory.
The average dam in Sweet Grass County is 76 years old. The most common purpose is irrigation. The tallest dam is Rosann Rosanna Dana at 50 ft.
Explore more: Oldest dams in Montana · Tallest dams · High risk dams · Largest reservoirs
Data note: Hazard potential describes the consequences if a dam failed; it does not predict the likelihood of failure. Inspection, condition, and emergency-plan fields can be incomplete or delayed. Check state dam-safety officials and local emergency managers for official guidance.
| Dam | Hazard | Condition | Height (ft) | Purpose | Year |
|---|---|---|---|---|---|
| Lower Glasston Dam | High | Poor | 30 | Irrigation | 1912 |
| Upper Glasston West Dam | High | Poor | 22 | Irrigation | 1912 |
| Upper Glasston North Dam | High | Poor | 20 | Irrigation | 1912 |
| East Boulder Tailings Dam | High | Satisfactory | 0 | Tailings | |
| Robbie | Significant | 25 | Irrigation | 1977 | |
| Ryan-tronrud Dam | Significant | 22 | Irrigation | 1956 | |
| Donald | Significant | 20 | Recreation | 1963 | |
| Rosann Rosanna Dana | Low | 50 | Other | 1939 | |
| Marstaeller Irrigation Dam | Low | 39 | Irrigation | 1984 | |
| Pioneer | Low | 25 | Other | 1968 | |
| Holzhey | Low | 21 | Irrigation | 1956 | |
| Cain | Low | 20 | Irrigation | 1965 | |
| Smoky Dam | Low | 20 | Other | 1968 | |
| Cramer (sweet Grass) | Low | 15 | Irrigation | 1960 | |
| Big Timber Sewage Lagoon | Low | 15 | Other | 1959 | |
| Beley Pond | Low | 14 | Irrigation | 1940 | |
| Burns Dam | Low | 12 | Irrigation | 1960 | |
| Lavold Dam | Low | 8 | Irrigation | 1913 |