Rivermatics

USGS Streamgage 09211200

Green River below Fontenelle Reservoir, WY

Green River below Fontenelle Reservoir, WY is USGS streamgage 09211200 in Wyoming, monitoring river discharge in hydrologic subbasin 14040103. It sits on the Green River, alongside 8 other gauges Rivermatics tracks on the same river. It drains a watershed of about 4,197 square miles. Discharge records at this site go back to 1963. Typical flow runs near 1,831 cfs in July and 1,255.3 cfs in April, with the higher of the two arriving in July. Rivermatics issues a daily machine-learned flow outlook for this gauge, reaching 14 days ahead, alongside daily high and low water-temperature forecasts.

View live conditions & forecast →

Gauge details

State
Wyoming
Drainage area
4,197 sq mi
Gauge elevation
6,400 ft
Subbasin (HUC-8)
14040103
Coordinates
42.02097, -110.04981
USGS site number
09211200
Records begin
1963-12-01 (63 years)
Rivermatics forecast
14-day flow outlook + water temperature

14-day flow forecast

Based on observations through for Green River below Fontenelle Reservoir, WY. 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
726 734 742
722 734 744
718 734 747
714 734 752
707 734 755
699 733 759
691 734 764
683 733 769
680 732 775
673 731 777
666 729 778
652 726 780
646 724 780
634 721 779

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 63 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 457.7 910.3 1,242.3
February 475.6 903 1,293.1
March 518.7 937.4 1,404.8
April 599 1,255.3 2,294.7
May 747.9 1,775.5 4,553.2
June 788.8 3,453.7 8,301.3
July 734.5 1,831 6,329
August 632.5 1,333.5 2,356.8
September 565.3 1,025.9 1,498.3
October 530.4 935.7 1,387.4
November 500.5 922.5 1,243.7
December 447.1 894.8 1,221.9

All values in cubic feet per second (cfs).

Common questions

When does Green River below Fontenelle Reservoir, WY normally run highest?
June, on the long-term record. The median daily flow that month is about 3,453.7 cfs, against 894.8 cfs in December, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
What is a normal flow for Green River below Fontenelle Reservoir, WY?
It depends on the month. In January, half of days historically fall near 910.3 cfs, with the middle 80% of days between 457.7 and 1,242.3 cfs. The month-by-month table on this page gives the full range.
How long has Green River below Fontenelle Reservoir, WY been measured?
Discharge records at USGS site 09211200 begin in 1963, about 63 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 Green River below Fontenelle Reservoir, WY?
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. A companion model forecasts each day's water-temperature high and low. 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 Green River below Fontenelle Reservoir, WY?
The gauge sits at 42.02097, -110.04981, in Wyoming, in hydrologic subbasin 14040103, at an elevation of about 6,400 feet, draining roughly 4,197 square miles.
Can I use Green River below Fontenelle Reservoir, WY 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 Green River

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

Other gauges in this region