Pioneer dam
Pioneer
Pioneer, also known as Millken Slough, is a private water structure located in Sweet Grass, Montana. Designed by the USDA NRCS and completed in 1968, this earth dam stands at 25 feet high and spans 200 feet in length. Its primary purpose is classified as "Other," with a low hazard potential and a normal storage capacity of 44 acre-feet.
Situated along the Pioneer Ditch, this water resource is regulated by the state of Montana through the DNRC, with inspection, enforcement, and permitting processes in place. The dam's location in a picturesque setting near Greycliff adds to its appeal for water resource and climate enthusiasts who may be interested in its construction, purpose, and historical significance. Despite not having a current condition assessment, Pioneer remains a notable feature in the local landscape.
With its unique design and historical background, Pioneer serves as a reminder of the importance of water management and conservation efforts in Montana. As a privately owned structure, its presence contributes to the overall water infrastructure of the region, highlighting the collaborative efforts between federal agencies like the Natural Resources Conservation Service and state regulators. For those interested in exploring water resources and climate impacts, Pioneer offers a valuable case study of dam construction and management in a rural setting.
Dam data reference
Condition Assessment
- Satisfactory
- No existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
- Fair
- No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action.
- Poor
- A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency.
- Unsatisfactory
- A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
- Not Rated
- The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Hazard Potential Classification
- High
- Dams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
- Significant
- Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environmental damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
- Low
- Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
- Undetermined
- Dams for which a downstream hazard potential has not been designated or is not provided.
Plan around the weather
Same NOAA / yr.no feed Snoflo's iOS app uses. Watch the precipitation column on the meteogram -- rain on the basin upstream typically lifts inflow 24-72 hours later.
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
5-day forecast table
Every 3 hours, broken out across temperature, snow, rain, humidity, and wind. Each cell is colour-coded relative to the column min/max.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day temperature & precipitation
Daily temperatures, snow, and rain projected over the next two weeks.
Nearby streamflow gauges
USGS streamgauges around Pioneer -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Boulder River At Big Timber Mt | 1,100 cfs | → |
| Stillwater River Near Absarokee Mt | 1,320 cfs | → |
| Shields River Nr Livingston Mt | 347 cfs | → |
| Yellowstone River Near Livingston Mt | 8,020 cfs | → |
| Red Lodge Cr Ab Cooney Re Nr Boyd Mt | 19 cfs | → |
| West Rosebud Creek Near Roscoe Mt | 79 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Pioneer.
Boat launches
- Howie Road Sweet Grass County
- Greycliff Bridge Sweet Grass County
- North Yellowstone Trail Road Sweet Grass County
- West Frontage Road Stillwater County
- Park County
- Us 89 Park County
Campgrounds
Fishing spots
Paddle runs
More reservoirs
Track Pioneer in the Snoflo app
Save this dam as a favorite and get the local NOAA / yr.no forecast plus regional flow context wherever you are.
About Pioneer
Where does the data for Pioneer come from?
Structural and regulatory data come from the U.S. Army Corps of Engineers' National Inventory of Dams (NID). Weather forecast comes from NOAA / yr.no -- the same feed Snoflo's iOS app uses.
How often is the report updated?
NID structural data refreshes annually as the Corps publishes updated assessments. The weather forecast refreshes throughout the day.
What does the Low hazard rating mean?
The Corps of Engineers' hazard potential classification grades probable consequences if the dam fails: High = probable loss of human life; Significant = no probable loss of human life but possible economic loss / environmental damage; Low = no probable loss of human life, only minor economic / environmental losses. See the Dam Data Reference card above for the full definitions.
What's "% of normal"?
The current storage value compared to the historical average storage on this calendar day. 100% = right on average; values above 100% mean above-normal storage (wet year); values below mean below-normal (dry year or drought).
Can I get alerts when storage crosses a threshold?
Yes -- alerts are managed in the Snoflo iOS app. Favorite this dam, set a threshold, and you'll get a push the moment conditions cross.
Other water bodies near here
Snoflo-tracked reservoirs and dams within driving distance of Pioneer.