Rivermatics

USGS Streamgage 12335100

Blackfoot River ab Nevada Creek near Helmville, MT

Blackfoot River ab Nevada Creek near Helmville, MT is USGS streamgage 12335100 in Montana, monitoring river discharge in hydrologic subbasin 17010203. It sits on the Blackfoot River, alongside 1 other gauge Rivermatics tracks on the same river. It drains a watershed of about 498 square miles. Discharge records at this site go back to 1999. Typical flow runs near 342.1 cfs in July and 277.9 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.

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Gauge details

State
Montana
Drainage area
498 sq mi
Gauge elevation
4,264 ft
Subbasin (HUC-8)
17010203
Coordinates
46.91879, -113.01499
USGS site number
12335100
Records begin
1999-10-01 (27 years)
Rivermatics forecast
14-day flow outlook

14-day flow forecast

Based on observations through for Blackfoot River ab Nevada Creek near Helmville, MT. 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
210 221 236
206 222 247
200 215 238
194 209 229
189 203 221
186 201 219
183 198 215
179 194 210
175 190 207
172 188 205
169 185 202
167 183 200
165 181 199
163 179 197

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 26 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 108.7 134 164.6
February 95.1 128.9 159.8
March 112.5 145 271.4
April 136.8 277.9 634
May 388.6 873.8 1,776.5
June 514.6 892.1 1,571
July 231.4 342.1 613.5
August 143.8 186.5 267
September 133.1 163.9 205
October 138.5 166.3 198.8
November 134.5 159.6 201
December 118.7 144.6 174.3

All values in cubic feet per second (cfs).

Common questions

When does Blackfoot River ab Nevada Creek near Helmville, MT normally run highest?
June, on the long-term record. The median daily flow that month is about 892.1 cfs, against 128.9 cfs in February, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
What is a normal flow for Blackfoot River ab Nevada Creek near Helmville, MT?
It depends on the month. In January, half of days historically fall near 134 cfs, with the middle 80% of days between 108.7 and 164.6 cfs. The month-by-month table on this page gives the full range.
How long has Blackfoot River ab Nevada Creek near Helmville, MT been measured?
Discharge records at USGS site 12335100 begin in 1999, about 27 years, covering roughly 8,812 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
Is there a flow forecast for Blackfoot River ab Nevada Creek near Helmville, MT?
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 Blackfoot River ab Nevada Creek near Helmville, MT?
The gauge sits at 46.91879, -113.01499, in Montana, in hydrologic subbasin 17010203, at an elevation of about 4,264 feet, draining roughly 498 square miles.
Can I use Blackfoot River ab Nevada Creek near Helmville, MT 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 Blackfoot River

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

Other gauges in this subbasin