Rivermatics

USGS Streamgage 12324590

Little Blackfoot River near Garrison, MT

Little Blackfoot River near Garrison, MT is USGS streamgage 12324590 in Montana, monitoring river discharge in hydrologic subbasin 17010201. It drains a watershed of about 414 square miles. Discharge records at this site go back to 1972. Typical flow runs near 107.1 cfs in July and 200.1 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, alongside daily high and low water-temperature forecasts.

View live conditions & forecast →

Gauge details

State
Montana
Drainage area
414 sq mi
Gauge elevation
4,363 ft
Subbasin (HUC-8)
17010201
Coordinates
46.51948, -112.79317
USGS site number
12324590
Records begin
1972-09-26 (54 years)
Rivermatics forecast
14-day flow outlook + water temperature

14-day flow forecast

Based on observations through for Little Blackfoot River near Garrison, 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
39 42.7 47
36.9 42.3 49.9
35.4 41.5 50.1
34.2 40.6 49.2
33.3 39.9 48.9
33 40.1 50.3
32.2 39.8 50.3
31.5 39.2 49.7
31.1 38.9 49.9
30.5 38.2 49.1
30 38 49.3
30.5 38.9 51.5
29.8 38.1 50.3
29.7 38.5 51.8

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 53 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 34.9 55.1 96.9
February 40.2 64.1 133.4
March 56 98.4 223.5
April 97.1 200.1 467.4
May 139.3 405.4 939.4
June 106 313.4 779.3
July 46.1 107.1 256.5
August 17.1 48.7 108.1
September 22 45 88.8
October 43.2 69.3 111.2
November 48.3 70.1 109.8
December 38.7 57.8 99.6

All values in cubic feet per second (cfs).

Common questions

When does Little Blackfoot River near Garrison, MT normally run highest?
May, on the long-term record. The median daily flow that month is about 405.4 cfs, against 45 cfs in September, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
What is a normal flow for Little Blackfoot River near Garrison, MT?
It depends on the month. In January, half of days historically fall near 55.1 cfs, with the middle 80% of days between 34.9 and 96.9 cfs. The month-by-month table on this page gives the full range.
How long has Little Blackfoot River near Garrison, MT been measured?
Discharge records at USGS site 12324590 begin in 1972, about 54 years, covering roughly 9,048 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
Is there a flow forecast for Little Blackfoot River near Garrison, 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. 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 Little Blackfoot River near Garrison, MT?
The gauge sits at 46.51948, -112.79317, in Montana, in hydrologic subbasin 17010201, at an elevation of about 4,363 feet, draining roughly 414 square miles.
Can I use Little Blackfoot River near Garrison, 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.

Other gauges in this subbasin