USGS Streamgage 06400875
Horsehead Creek at Oelrichs, SD
Horsehead Creek at Oelrichs, SD is USGS streamgage 06400875 in South Dakota, monitoring river discharge in hydrologic subbasin 10120106. It drains a watershed of about 188 square miles. Discharge records at this site go back to 1983. Typical flow runs near 0 cfs in July and 0.2 cfs in April, with the higher of the two arriving in April. Rivermatics issues a daily machine-learned flow outlook for this gauge, reaching 14 days ahead.
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Gauge details
- State
- South Dakota
- Drainage area
- 188 sq mi
- Gauge elevation
- 3,319 ft
- Subbasin (HUC-8)
- 10120106
- Coordinates
- 43.18806, -103.22611
- USGS site number
- 06400875
- Records begin
- 1983-06-01 (43 years)
- Rivermatics forecast
- 14-day flow outlook
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 43 years of data), averaged within each month. These describe the historical normal range — they are not a forecast and not today's reading.
| Month | Low p10 | Typical p50 | High p90 | Range |
|---|---|---|---|---|
| January | 0 | 0 | 0.4 | |
| February | 0 | 0.1 | 2.3 | |
| March | 0 | 0.1 | 21.3 | |
| April | 0 | 0.2 | 22.2 | |
| May | 0 | 0.3 | 46.7 | |
| June | 0 | 0.2 | 52.1 | |
| July | 0 | 0 | 2.4 | |
| August | 0 | 0 | 0.3 | |
| September | 0 | 0 | 0 | |
| October | 0 | 0 | 0.3 | |
| November | 0 | 0 | 0.3 | |
| December | 0 | 0 | 0.4 |
All values in cubic feet per second (cfs).
Common questions
- When does Horsehead Creek at Oelrichs, SD normally run highest?
- May, on the long-term record. The median daily flow that month is about 0.3 cfs, against 0 cfs in January, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
- What is a normal flow for Horsehead Creek at Oelrichs, SD?
- It depends on the month. In January, half of days historically fall near 0 cfs, with the middle 80% of days between 0 and 0.4 cfs. The month-by-month table on this page gives the full range.
- How long has Horsehead Creek at Oelrichs, SD been measured?
- Discharge records at USGS site 06400875 begin in 1983, about 43 years, covering roughly 9,200 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
- Is there a flow forecast for Horsehead Creek at Oelrichs, SD?
- Yes. Rivermatics trains a machine-learned model — a temporal-fusion transformer — on this basin's observed flows, weather, and snowpack, and issues a daily flow outlook reaching 14 days ahead: a median estimate inside a confidence band, not a single number to bet on. Every forecast is scored against days the model never trained on, and that track record is published on the live gauge screen. Open live conditions to see the current outlook.
- Where is Horsehead Creek at Oelrichs, SD?
- The gauge sits at 43.18806, -103.22611, in South Dakota, in hydrologic subbasin 10120106, at an elevation of about 3,319 feet, draining roughly 188 square miles.
- Can I use Horsehead Creek at Oelrichs, SD data for flood or safety decisions?
- No. Rivermatics provides estimates, not guarantees, and the readings and forecasts here may be delayed, inaccurate, or wrong. Do not use them for navigation or for any safety, rescue, or emergency decision. Check the National Weather Service and USGS directly, and use your own judgment.