St. Mary River Near Babb flow report
As of July 15, 2026, St. Mary River Near Babb is flowing at 1,430 cfs with a gage height of 3.64 ft, holding steady over the past 24 hours. Source: USGS gauge #05017500, refreshed throughout the day.
Historical Data
St. Mary River Near Babb at a glance
How St. Mary River Near Babb is running right now, where it sits on the map, and the key gauge stats.
St. Mary River Near Babb is flowing at 1,430 cfs, with the water sitting 3.64 ft at the gage. Flow has held roughly steady over the past 24 hours.
This is USGS gauge #05017500 in Montana. Over the past 10 days the average has been 1,752 cfs, peaking at 2,450 cfs.
For real-time updates and historical context, see the realtime view or the historical comparison. Browse other gauges in the Montana flow report.
Streamflow Forecast
Over the next 5 days, St. Mary River Near Babb Mt is expected to recede from today's 1430 cfs, toward roughly 1262 cfs by 2026-07-20 (likely range 871-1830 cfs) -- drier than normal for the date.
Powered by PULSE — Snoflo’s forecast engine, trained on this gauge’s full record of storms, snowmelt, and dry spells.
How does this compare to past years?
Year-over-year overlay, annual peak discharge, the full distribution of daily flows on record, and the gauge's rating curve.
Weather Forecast
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.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day forecast
Daily temperatures, snow, and rain projected over the next two weeks.
St. Mary River Near Babb
Mary River near Babb, MT stream gauge measures the flow rate and water level of the St. Mary River. The river is fed by glacier meltwater from Glacier National Park and other small tributaries. The largest tributary is the Milk River, which joins the St. Mary River near the town of Shelby. The river has been altered by the construction of the St. Mary Diversion Dam, which diverts water from the river into the Milk River for irrigation purposes. Seasonal trends show lower flow rates in the winter months and higher flow rates in the spring and early summer. Interesting hydrological features include the St. Mary River's unique turquoise color, caused by glacial silt, and its designation as a Wild and Scenic River.
Nearby streamflow levels
Cross-check St. Mary River Near Babb's discharge against nearby gauges to spot whether the change here is local or regional.
| Gauge | Streamflow |
|---|---|
| St. Mary River Near Babb Mt | 1,430 cfs |
| St. Mary Canal At Intake Near Babb Mt | 54 cfs |
| St. Mary Canal At St. Mary Crossing Near Babb Mt | 599 cfs |
| Swiftcurrent Creek At Many Glacier Mt | 214 cfs |
| Swiftcurrent Cr Ab Swiftcurrent Lk At Many Glacier | 113 cfs |
| N F Milk River Ab St Mary Ca Nr Browning Mt | 8 cfs |
Nearby snowpack data
Snowpack at SNOTEL stations near St. Mary River Near Babb. Spring snowmelt is the dominant driver of streamflow in mountain basins -- a deep snowpack upstream means more runoff later in the season.
| SNOTEL station | Snowpack |
|---|---|
| Many Glacier | 0 in |
| Nohrsc Many Glacier | 0 in |
| Flattop Mtn. | 0 in |
| Nohrsc Flattop Mtn. | 0 in |
| West Glacier | 0 in |
| Emery Creek | 1 in |
River levels & flood safety
- Read the level before you go
- A river that's runnable at one flow can be deadly at another. Check current discharge and gage height — like the values shown above — against the flood-stage thresholds, and remember levels can spike fast after rain or a dam release.
- Respect cold water
- Snowmelt rivers run cold even in summer. Sudden immersion triggers cold-water shock and saps strength within minutes. Wear a PFD, dress for the water temperature (not the air), and never wade or paddle alone.
- Watch for swiftwater hazards
- Strainers (downed trees), undercut rocks, and low-head dams are the deadliest features on moving water. High, fast, muddy water hides them. If in doubt, scout from shore and portage.
- Mind flash floods & releases
- Narrow canyons can flood from a storm miles upstream, and dam-controlled reaches can rise without warning. Know the forecast, the release schedule, and your exit before you launch.
Track St. Mary River Near Babb in the Snoflo app
Save this gauge as a favorite, set push alerts when streamflow crosses a threshold (e.g. "alert me when St. Mary River Near Babb crosses 5,000 cfs"), and Snoflo's iOS app will push the moment USGS reports the crossing.
About St. Mary River Near Babb
Where does the streamflow data for St. Mary River Near Babb come from?
Discharge, gage height, and water temperature come directly from the USGS streamflow gauge 05017500. Snoflo refreshes the time series throughout the day. Forecasts come from the NOAA / yr.no feed Snoflo's iOS app uses.
How often is the report updated?
USGS gauges report continuously (typically every 15 minutes). Snoflo pulls fresh values throughout the day — look for the "as of" timestamp on the streamflow hero card.
What's the difference between discharge and gage height?
Discharge (cubic feet per second, or cfs) is the volume of water flowing past the gauge each second. Gage height is how high the water sits at the gauge (feet). They're related by a rating curve specific to each gauge — higher water means more flow, but the exact ratio depends on channel shape.
How is "percent of median" calculated?
Today's discharge is compared to the historical median discharge on this calendar day across the gauge's full record. 100% = right on median; 200% = a very high year; 30% = a drought-level low.
What are flood stages, and is this river safe right now?
Flood stages are NWS-defined gage-height thresholds — Action, Minor, Moderate, Major — marking when nearby roads or floodplains start to be affected. "Safe" depends on your activity and skill: a level that's a fun paddle for an expert can be lethal for a wader. Always check the current level against the thresholds above and the safety links, and when in doubt, stay off the water.
Can I get alerts when St. Mary River Near Babb rises?
Yes — flow alerts are managed in the Snoflo iOS app. Favorite this gauge, set a streamflow threshold (e.g. "alert me when discharge crosses 5,000 cfs"), and you'll get a push the moment USGS reports the crossing.
Access the free St. Mary River Near Babb report
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