South Fork Boise River at Anderson Ranch Dam, ID
Southwest & South-Central Idaho · USGS gauge 13190500 · Updated Oct 24, 2:37 PM PDT · USGS data, provisional
Reading time: Oct 24, 2:15 PM PDT · Provisional data
Flow is in a typical range for the date. Rivers are generally easiest to fish and float when they are near their normal flow, but this status says nothing about water clarity, hatches, hazards such as wood in the river, or dam releases.
- Vs. normal for this date
- 40th percentile
- Typical range (25th–75th)
- 248–320 cfs
- Median for this date
- 300 cfs
- 7-day low / high
- 248 / 319 cfs
Plain-language explanation
South Fork Boise River at Anderson Ranch Dam is flowing at 295 cubic feet per second (cfs) as of Oct 24, 2:15 PM PDT. That is in the normal range for this time of year: lower than about 60% of the daily flows this gauge has recorded for this date (give or take 7 days) over 84 years of record (1943–2026).
The middle half of those historical flows runs from 248 to 320 cfs, with a median of 300 cfs; the lowest 10% of days are at or below 115 cfs and the highest 10% at or above 510 cfs.
Over the last 24 hours the flow has been steady (+0.0%). In the last 7 days it ranged from 248 to 319 cfs.
Regulated flow: upstream dams or diversions influence this gauge, so the “normal range” above reflects managed flows and can differ from natural river behavior.
Why this status: Flow is within the range this gauge normally sees at this time of year (or the deviation is too small in absolute terms to matter).
Quick answers
Is the South Fork Boise River at Anderson Ranch Dam fishable today?
Flowcast's status for the South Fork Boise River at Anderson Ranch Dam is “Fishable/Floatable”: flow is 295 cfs, within the range this gauge normally sees at this time of year, at the 40th percentile for this date (as of Oct 24, 2:15 PM PDT). That describes flow only. It says nothing about water clarity, temperature, fish activity, access or fishing regulations.
What is the current flow of the South Fork Boise River at Anderson Ranch Dam?
295 cubic feet per second at USGS gauge 13190500 as of Oct 24, 2:15 PM PDT, provisional data.
Is the South Fork Boise River at Anderson Ranch Dam too high or too low right now?
Neither: it is inside the typical range for the date (248 to 320 cfs).
Is the South Fork Boise River at Anderson Ranch Dam rising or falling?
Over the last 24 hours the flow has been steady (+0.0%).
What is a normal flow for the South Fork Boise River at Anderson Ranch Dam in October?
For this date (give or take 7 days) the median is 300 cfs and the middle half of days runs 248 to 320 cfs, over 84 years of USGS record.
7-day trend
Hourly flow in cfs, Pacific time. The shaded band is the typical range (25th–75th percentile) for this date, shown when it falls within the chart.
| Day (Pacific) | Mean cfs | Percentile | Status that day |
|---|---|---|---|
| Sun Oct 18 | 306 | 63rd | Fishable/Floatable |
| Mon Oct 19 | 302 | 56th | Fishable/Floatable |
| Tue Oct 20 | 309 | 69th | Fishable/Floatable |
| Wed Oct 21 | 300 | 54th | Fishable/Floatable |
| Thu Oct 22 | 304 | 58th | Fishable/Floatable |
| Fri Oct 23 | 298 | 45th | Fishable/Floatable |
| Sat Oct 24 (so far) | 292 | 37th | Fishable/Floatable |
Seasonal context
Shaded band: 10th–90th percentile of daily flows through the year; dashed line: median. Log scale. Dot: today's flow. Based on 84 years of USGS daily data (1943–2026).
Guide, outfitter or fly shop on this river? List your service on Flowcast (free early listings, launching).
Official resources
- USGS site page for gauge 13190500 (USGS: live readings, history, station details)
- Idaho Fishing Planner: waters, rules, access (IDFG)
Links go to the agencies' own websites and were checked as working. Flowcast does not summarize fishing or boating rules: regulations and closures change, and the agency pages are the authority.
About this gauge
- USGS site
- USGS-13190500
- USGS name
- Sf Boise River At Anderson Ranch Dam Id
- Drainage area
- 978 sq mi
- Location
- 43.3436, -115.4775
- Record in this analysis
- 1943–2026
Nearby gauges
- Boise River near Twin Springs, ID Fishable/Floatable 416 cfs · about 26 mi away (straight line)
- Boise River at Glenwood Bridge, near Boise, ID Fishable/Floatable 225 cfs · about 46 mi away (straight line)
- Big Wood River at Hailey (total flow), ID Fishable/Floatable 214 cfs · about 59 mi away (straight line)
Browse this region
Questions about what the status means? How to read a status · FAQ.