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Boulder River in Montana

River36.3 mi
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Around here

Around Boulder River

Galena Gulch Campground10.1 mi5 mi

Data Source: Recreation.gov · Source: USGS GNIS · Public land: USGS PAD-US

About this river

Boulder River is a 36.3 mile river. Streamflow is measured at the USGS gauge Boulder River near Boulder, MT (site 06033000). The National Hydrography Dataset places it at stream order 5. Reach geometry comes from the USGS National Hydrography Dataset.

Typical flow by month

1929 to 2026

Boulder River typically runs highest in May, at a median 418 cfs, and lowest in September, at 22 cfs. The highest flow on record for any single day is 2,950 cfs, in 2011.

Show the numbers
Typical flow by month at Boulder River near Boulder, MT, in cfs
MonthTypical (cfs)Usual range (cfs)
January2821 to 35
February3023 to 37
March3731 to 53
April13780 to 222
May418308 to 617
June342189 to 578
July6039 to 105
August2314 to 41
September2214 to 33
October3324 to 52
November3525 to 45
December2822 to 36

Typical is the median of each month’s daily median values, and the usual range runs from the median 25th to the median 75th percentile, across about 84 years of record. Statistics published by the US Geological Survey for Boulder River near Boulder, MT (site 06033000). Conditions on any given day can fall well outside the usual range. Check the current reading before you go.

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