Rivermatics

USGS Streamgage 06019500

Ruby River above reservoir near Alder, MT

Ruby River above reservoir near Alder, MT is USGS streamgage 06019500 in Montana, monitoring river discharge in hydrologic subbasin 10020003. It sits on the Ruby River, alongside 2 other gauges Rivermatics tracks on the same river. It drains a watershed of about 534 square miles. Discharge records at this site go back to 1938. Typical flow runs near 173.7 cfs in July and 148.3 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.

View live conditions & forecast →

Gauge details

State
Montana
Drainage area
534 sq mi
Gauge elevation
5,412 ft
Subbasin (HUC-8)
10020003
Coordinates
45.19232, -112.14282
USGS site number
06019500
Records begin
1938-05-01 (88 years)
Rivermatics forecast
14-day flow outlook

14-day flow forecast

Based on observations through for Ruby River above reservoir near Alder, 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
80.5 83.6 86.4
78.2 82.4 86.6
75.9 81.3 86.8
74.6 80.9 87.8
73.4 80.5 88.3
74.1 82.1 92
74.4 83.3 94.3
72.8 82.4 93.7
71.9 81.9 93.8
71.8 82.2 95
71.1 81.7 95
70.7 81.6 95.4
69.9 81.2 95.1
69.2 80.7 94.9

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 87 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 85 101.4 121.1
February 84.9 100.2 118.4
March 88.7 104.6 136.2
April 104.6 148.3 247.5
May 199.3 365.7 717.9
June 190.2 402.3 858.2
July 95.2 173.7 321.6
August 77 111.7 176.8
September 84.7 111.1 152.7
October 96.5 124.3 157.6
November 101.4 118.9 146.1
December 90.5 107.6 130.1

All values in cubic feet per second (cfs).

Common questions

When does Ruby River above reservoir near Alder, MT normally run highest?
June, on the long-term record. The median daily flow that month is about 402.3 cfs, against 100.2 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 Ruby River above reservoir near Alder, MT?
It depends on the month. In January, half of days historically fall near 101.4 cfs, with the middle 80% of days between 85 and 121.1 cfs. The month-by-month table on this page gives the full range.
How long has Ruby River above reservoir near Alder, MT been measured?
Discharge records at USGS site 06019500 begin in 1938, about 88 years, covering roughly 9,068 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
Is there a flow forecast for Ruby River above reservoir near Alder, 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 Ruby River above reservoir near Alder, MT?
The gauge sits at 45.19232, -112.14282, in Montana, in hydrologic subbasin 10020003, at an elevation of about 5,412 feet, draining roughly 534 square miles.
Can I use Ruby River above reservoir near Alder, 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 Ruby River

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

Other gauges in this subbasin