Rivermatics

USGS Streamgage 06402600

Cheyenne River near Buffalo Gap, SD

Cheyenne River near Buffalo Gap, SD is USGS streamgage 06402600 in South Dakota, monitoring river discharge in hydrologic subbasin 10120109. It sits on the Cheyenne River, alongside 8 other gauges Rivermatics tracks on the same river. It drains a watershed of about 9,792 square miles. Discharge records at this site go back to 1968. Typical flow runs near 53.5 cfs in July and 69.7 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.

View live conditions & forecast →

Gauge details

State
South Dakota
Drainage area
9,792 sq mi
Gauge elevation
2,818 ft
Subbasin (HUC-8)
10120109
Coordinates
43.50198, -103.07394
USGS site number
06402600
Records begin
1968-10-01 (58 years)
Rivermatics forecast
14-day flow outlook

14-day flow forecast

Based on observations through for Cheyenne River near Buffalo Gap, 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
52.2 55.3 58.7
50.2 54.7 60.1
49.3 54.7 61.6
48.7 55.3 64.7
48.5 55.9 66.2
48.1 56.4 68.5
49.6 62.7 89.5
51.8 66.6 98.9
50.6 63.8 89.2
49 61.1 81
48.2 59.6 76.3
46.9 57.9 73
46.3 57.7 73.2
46 57.2 71.9

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 58 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 41.7 61.4 108.9
February 49 65.6 122
March 54.4 70.3 411.6
April 47.7 69.7 258.4
May 42.7 69.6 931.8
June 36.5 62.3 817.3
July 25.6 53.5 193.6
August 39.5 63.5 116.8
September 49.6 68.3 98.6
October 55.3 70.5 117.2
November 58.1 70.4 107.1
December 40.6 66.1 114.1

All values in cubic feet per second (cfs).

Common questions

When does Cheyenne River near Buffalo Gap, SD normally run highest?
October, on the long-term record. The median daily flow that month is about 70.5 cfs, against 53.5 cfs in July, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
What is a normal flow for Cheyenne River near Buffalo Gap, SD?
It depends on the month. In January, half of days historically fall near 61.4 cfs, with the middle 80% of days between 41.7 and 108.9 cfs. The month-by-month table on this page gives the full range.
How long has Cheyenne River near Buffalo Gap, SD been measured?
Discharge records at USGS site 06402600 begin in 1968, about 58 years, covering roughly 6,948 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
Is there a flow forecast for Cheyenne River near Buffalo Gap, 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 Cheyenne River near Buffalo Gap, SD?
The gauge sits at 43.50198, -103.07394, in South Dakota, in hydrologic subbasin 10120109, at an elevation of about 2,818 feet, draining roughly 9,792 square miles.
Can I use Cheyenne River near Buffalo Gap, 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 Cheyenne River

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

Other gauges in this subbasin