Rivermatics

USGS Streamgage 06409000

Castle Creek above Deerfield Reservoir near Hill City, SD

Castle Creek above Deerfield Reservoir near Hill City, SD is USGS streamgage 06409000 in South Dakota, monitoring river discharge in hydrologic subbasin 10120110. It sits on the Castle Creek, alongside 1 other gauge Rivermatics tracks on the same river. It drains a watershed of about 79 square miles. Discharge records at this site go back to 1948. Typical flow runs near 11.8 cfs in July and 15.5 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
79 sq mi
Gauge elevation
5,927 ft
Subbasin (HUC-8)
10120110
Coordinates
44.01361, -103.83
USGS site number
06409000
Records begin
1948-07-01 (78 years)
Rivermatics forecast
14-day flow outlook

14-day flow forecast

Based on observations through for Castle Creek above Deerfield Reservoir near Hill City, SD. Each day carries a median estimate and the band the model expects the flow to fall within — not a single number to plan against. Forecasts are re-issued daily; see the live screen for the current outlook.

Forecast daily mean discharge in cubic feet per second, by date
Date Low p10 Expected p50 High p90 Range
7.3 7.7 8.3
6.9 7.5 8.1
7.2 7.8 9.3
6.9 7.6 8.7
7 7.8 9.2
7.3 8.4 10.7
7 7.9 9.5
6.8 7.7 9.1
6.7 7.6 9
6.6 7.6 9
6.5 7.5 8.7
6.4 7.4 8.6
6.4 7.4 8.6
6.6 7.6 9.1

All values in cubic feet per second (cfs). Estimates only — do not use them for navigation or for any safety, rescue, or emergency decision.

Typical flow by month

Long-term daily discharge percentiles from the USGS record (up to 78 years of data), averaged within each month. These describe the historical normal range — they are not a forecast and not today's reading.

Historical monthly discharge percentiles in cubic feet per second
Month Low p10 Typical p50 High p90 Range
January 5.3 9.1 16.2
February 5.8 9.2 16.6
March 6.3 11.3 19.7
April 9.8 15.5 27.5
May 10.1 16.2 32
June 8.4 13.7 32.3
July 7.1 11.8 25.5
August 6.6 10.9 21.2
September 6.7 10.8 19.8
October 6.7 10.9 19.5
November 6.3 10.2 17.9
December 5.8 9.2 17.5

All values in cubic feet per second (cfs).

Common questions

When does Castle Creek above Deerfield Reservoir near Hill City, SD normally run highest?
May, on the long-term record. The median daily flow that month is about 16.2 cfs, against 9.1 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 Castle Creek above Deerfield Reservoir near Hill City, SD?
It depends on the month. In January, half of days historically fall near 9.1 cfs, with the middle 80% of days between 5.3 and 16.2 cfs. The month-by-month table on this page gives the full range.
How long has Castle Creek above Deerfield Reservoir near Hill City, SD been measured?
Discharge records at USGS site 06409000 begin in 1948, about 78 years, covering roughly 9,103 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
Is there a flow forecast for Castle Creek above Deerfield Reservoir near Hill City, 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 Castle Creek above Deerfield Reservoir near Hill City, SD?
The gauge sits at 44.01361, -103.83, in South Dakota, in hydrologic subbasin 10120110, at an elevation of about 5,927 feet, draining roughly 79 square miles.
Can I use Castle Creek above Deerfield Reservoir near Hill City, 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.

Upstream and downstream on the Castle Creek

Every gauge Rivermatics tracks on this river, ordered by drainage area — upstream first. See the Castle Creek in full.

Other gauges in this subbasin