Around here
Around Big Sioux River
Public land: USGS PAD-US
About this river
Big Sioux River is a 62.1 mile river. Streamflow is measured at the USGS gauge Big Sioux River near Castlewood, SD (site 06479525). The National Hydrography Dataset places it at stream order 6. Reach geometry comes from the USGS National Hydrography Dataset.
Typical flow by month
1977 to 2026
Big Sioux River typically runs highest in April, at a median 159 cfs, and lowest in January, at 10 cfs. The highest flow on record for any single day is 4,090 cfs, in 1997.
Show the numbers
| Month | Typical (cfs) | Usual range (cfs) |
|---|---|---|
| January | 10 | 2.1 to 27 |
| February | 10 | 2.2 to 33 |
| March | 51 | 20 to 192 |
| April | 159 | 38 to 472 |
| May | 134 | 34 to 383 |
| June | 100 | 33 to 216 |
| July | 56 | 14 to 114 |
| August | 37 | 9.3 to 86 |
| September | 25 | 8.6 to 60 |
| October | 23 | 11 to 71 |
| November | 24 | 11 to 60 |
| December | 18 | 7.8 to 38 |
Typical is the median of each month’s daily median values, and the usual range runs from the median 25th to the median 75th percentile, across about 49 years of record. Statistics published by the US Geological Survey for Big Sioux River near Castlewood, SD (site 06479525). Conditions on any given day can fall well outside the usual range. Check the current reading before you go.
Boat access nearby
8 mapped launches sit in the mapped area of Big Sioux River, all of them public access. Ramp data comes from the USGS national boat-ramp inventory.
- Campbell Public Water AccessPublic
- Sinai Public Water AccessPublic
- West 81 Public Water AccessPublic
- East 81 Public Water AccessPublic
- Goldsmith Public Water AccessPublic
- Oakwood - West Public Water AccessPublic
- Oakwood Lakes State ParkPublic
- Oakwood - North Public Water AccessPublic
Made to print
Put Big Sioux River on your wall
This river section as an art print, drawn over the real terrain with its miles, plus the trails, roads and peaks around it. Pick the colors and the size, and see the finished print before you buy. From $39, shipping included.
Embed this gauge on your site
Paste this snippet anywhere, an outfitter page, a club site, a trip report, to show Big Sioux River's live streamflow, water level and 7-day trend. It reads the USGS gauge directly, updates itself, and links back here.
See every free widget you can put on your site, including live conditions and a 7 day forecast.
