The monitoring network within this area

Hydrionis holds 464 values from 2 gauges within it. Discharge is a property of a gauge and its reach, not of this drainage area, so this page reports the network and its records rather than a single figure.

Gauges

464

Values held

1890–2026

Record spans

Gauges within the Upper Missouri-Dearborn huc8 subbasin

2 monitoring points, positioned as the publisher records them.

Flood peaks, as measured

This gauge's flood record, as measured. Unlike a daily mean it is the discharge at the moment the river was highest, which is the figure flood frequency analysis is built on.

Largest measured flow of each year at Missouri River at Fort Benton MT

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1891–2025.

Show relevant events (1 event)Shading marks when something was recorded, not what caused the line.

Published by the gauge's own operator from its sub-daily record; Hydrionis stores the figure rather than recomputing it. A year the gauge did not cover produces no value rather than a low one, and the gaps are stated below the chart. A peak is a property of this gauge and its reach: a larger flood upstream or downstream of it is not in this series.

What the shaded periods are (1 event)

A shaded period marks when something was recorded, not what caused the shape of the line. Where the two coincide, they coincided.

Documented record — A documented event, compiled from cited sources after it happened. The dates are as good as the record, which for older events can mean the month rather than the day.

Event	Type	Period	Standing	Authority
Hurricane Katrina water and sanitation collapse	Flood	2005-08-29 – 2005-09-30	Documented record	Compiled record

Not shown on this chart

The 1976 drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
The 2022 drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
Yorkshire drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
Cantareira water crisis, São Paulo — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
Cape Town Day Zero — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
European drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.

View the data behind this chart

Underlying data
Period	Missouri River at Fort Benton MT (m³/s)
1891	1,124
1892	1,863
1893	1,008
1894	1,566
1895	606
1896	1,144
1897	773
1898	1,065
1899	1,303
1901	861
1902	900
1903	861
1904	773
1905	450
1906	561
1907	1,345
1908	3,964
1909	1,540
1910	665
1911	903
1913	1,246
1914	818
1915	869
1916	1,376
1917	1,365
1918	793
1919	394
1920	869
1921	912
1922	971
1923	719
1924	688
1925	844
1926	578
1928	946
1929	609
1931	368
1932	665
1933	742
1934	555
1935	487
1936	680
1937	300
1938	866
1939	507
1940	385
1941	433
1942	940
1943	1,090
1944	878
1945	677
1946	535
1947	968
1948	1,495
1949	643
1950	818
1951	779
1952	694
1953	2,229
1954	507
1955	450
1956	881
1957	606
1958	580
1959	779
1960	583
1961	292
1962	651
1963	629
1964	2,192
1965	881
1967	1,093
1968	807
1969	833
1970	799
1971	753
1972	694
1974	827
1975	1,756
1976	940
1978	665
1979	583
1980	796
1981	1,447
1982	827
1983	665
1984	739
1986	606
1987	337
1988	237
1989	450
1990	430
1991	682
1992	232
1993	668
1994	436
1995	801
1996	855
1997	1,039
1998	821
1999	555
2000	223
2001	188
2002	450
2003	402
2004	258
2005	484
2006	564
2007	405
2008	903
2009	580
2010	850
2011	1,492
2012	459
2013	436
2014	487
2015	354
2016	379
2017	481
2018	1,141
2019	801
2020	566
2021	382
2022	323
2023	680
2024	354
2025	255

About this series

Everything below is a property of the data rather than a rating of it. There is deliberately no single confidence score: how much a gap matters depends on what you are about to do with the series, and only you know that.

Source	United States Geological Survey — National Water Information System · US Government work — public domain
How the values came to exist	Measured
Period held	1891–2025
Completeness	94.1% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	8 separate periods inside 1891–2025 hold no value. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1891 and is not continuous from it: 135 years separate the first value from the last, and 94% of the years between them are held. The span is not the record.
Last read from the publisher	2026-10-01
Redistribution	Permitted by the upstream licences
Commercial reuse	Permitted by the upstream licences. No Hydrionis access tier can widen this.
Methodology	How this was produced

How much of the rain came back out

A discharge in cubic metres per second cannot be compared with anything: the larger number may only mean the larger catchment. Divided by the area draining to the gauge it becomes a depth of water over that land, which answers a question a reader already has — of the rain that fell here, how much came back out as river?

Water leaving the catchment above Missouri River at Fort Benton MT, as a depth

The year's flow spread over the land draining to this gauge, in millimetres — the same unit rainfall is measured in. 1891–2025.

Show relevant events (1 event)Shading marks when something was recorded, not what caused the line.

Computed by Hydrionis from the published annual mean flow and the catchment area the station's own publisher states. It is not a water balance: the difference between rainfall and runoff is not evaporation alone but also change in groundwater storage, water abstracted and taken elsewhere, and water imported by transfer schemes — which is why a catchment can yield more runoff than the rain that fell on it without anything being measured wrongly. A different area figure rescales every value here by the ratio between them.

What the shaded periods are (1 event)

A shaded period marks when something was recorded, not what caused the shape of the line. Where the two coincide, they coincided.

Documented record — A documented event, compiled from cited sources after it happened. The dates are as good as the record, which for older events can mean the month rather than the day.

Event	Type	Period	Standing	Authority
Hurricane Katrina water and sanitation collapse	Flood	2005-08-29 – 2005-09-30	Documented record	Compiled record

Not shown on this chart

The 1976 drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
The 2022 drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
Yorkshire drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
Cantareira water crisis, São Paulo — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
Cape Town Day Zero — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.
European drought — This event’s area does not contain this chart’s subject. Sharing a country is not sharing an event, so it is not drawn.

View the data behind this chart

Underlying data
Period	Missouri River at Fort Benton MT (mm)
1891	122
1892	142
1893	129
1894	168
1895	100
1896	129
1897	114
1898	137
1899	155
1900	105
1901	95.0
1902	93.0
1903	105
1904	117
1905	68.0
1906	85.0
1907	154
1908	170
1909	144
1910	114
1911	107
1912	134
1913	151
1914	121
1915	129
1916	159
1917	160
1918	109
1919	63.0
1920	115
1921	111
1922	118
1923	110
1924	90.0
1925	119
1926	97.0
1927	161
1928	135
1929	96.0
1930	74.0
1931	55.0
1932	79.0
1933	86.0
1934	65.0
1935	63.0
1936	66.0
1937	49.0
1938	90.0
1939	74.0
1940	62.0
1941	65.0
1942	111
1943	135
1944	96.0
1945	85.0
1946	89.0
1947	126
1948	149
1949	93.0
1950	108
1951	120
1952	115
1953	107
1954	75.0
1955	84.0
1956	99.0
1957	94.0
1958	94.0
1959	106
1960	90.0
1961	67.0
1962	92.0
1963	97.0
1964	134
1965	164
1966	86.0
1967	131
1968	127
1969	137
1970	138
1971	138
1972	130
1973	81.0
1974	120
1975	181
1976	154
1977	78.0
1978	138
1979	104
1980	117
1981	134
1982	143
1983	122
1984	139
1985	91.0
1986	107
1987	68.0
1988	62.0
1989	84.0
1990	79.0
1991	99.0
1992	62.0
1993	131
1994	85.0
1995	129
1996	131
1997	153
1998	120
1999	105
2000	72.0
2001	62.0
2002	69.0
2003	76.0
2004	66.0
2005	81.0
2006	87.0
2007	74.0
2008	103
2009	104
2010	117
2011	178
2012	91.0
2013	74.0
2014	102
2015	80.0
2016	77.0
2017	94.0
2018	138
2019	115
2020	101
2021	71.0
2022	70.0
2023	107
2024	79.0
2025	70.0

About this series

Source	United States Geological Survey — National Water Information System · US Government work — public domain
How the values came to exist	Derived Computed by Hydrionis
Period held	1891–2025
Completeness	100.0% of the periods in that span are held.
Continuity	Continuous: every year from 1891 to 2025 is held.
Inputs last read	2026-10-01 · when the records this was computed from were last read from their publishers
Calculation date	2026-08-24 · when the calculation method was last versioned, not a reading of any publisher
Redistribution	Permitted by the upstream licences
Commercial reuse	Permitted by the upstream licences. No Hydrionis access tier can widen this.
Methodology	How this was produced

Every gauge Hydrionis holds within this area

Gauges within the Upper Missouri-Dearborn and what each holds
Gauge	Measures	Values	Record
Missouri River at Fort Benton MT	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	438	1890–2026
Missouri River at Cascade MT	catchment area, annual maximum river flow	26	1903–2026

How these gauges were attached to this water

Assigned by the publisher to a numbered basin Every gauge here is assigned to this drainage area by its own publisher, which issues the area an official code — 10030102. A drainage area is not a river: it contains the tributaries as well as the main channel, and a gauge in it may be on any of them.

What each gauge’s link to this water rests on
Gauge	Evidence	Established
Missouri River at Fort Benton MT	Stated by the publisher — USGS site service, huc_cd field — https://waterservices.usgs.gov/nwis/site/ ; named from the USGS Watershed Boundary Dataset 8-digit HU (Subbasin) layer — https://hydro.nationalmap.gov/arcgis/rest/services/wbd/MapServer/4	2026-10-02
Missouri River at Cascade MT	Stated by the publisher — USGS site service, huc_cd field — https://waterservices.usgs.gov/nwis/site/ ; named from the USGS Watershed Boundary Dataset 8-digit HU (Subbasin) layer — https://hydro.nationalmap.gov/arcgis/rest/services/wbd/MapServer/4	2026-10-02

What this record holds

Hydrionis decides which waters get a page, and which of those are offered to search, from what is actually held rather than from how the page reads. Five signals are counted; this record has 3 of them, which makes it a full profile.

Information-gain signals held for this water body
Signal	Held	Counts
Gauges holding a real record	1	no
Years spanned	137	yes, 20 or more
Values held	464	no
Distinct measurements	5	yes, 2 or more
Publishers measuring it	2	yes, 2 or more
Official identifiers	1	recorded, not counted

Use this data

Machine-readable JSON /api/v1/observations/by-subject/gauge-usgs-06090800.json
How to cite this, and who you must credit
How these figures were produced
Request this at a different scale, format or geography

No bulk download is offered here, which is a licence position rather than a product one: at least one contributing publisher does not permit redistribution. The values can be read on the page, cited, and pointed to at source.

Attribution and citation

Suggested citation for Hydrionis

Hydrionis (2026), Upper Missouri-Dearborn gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-upper-missouri-dearborn/

Cite Hydrionis where you rely on values Hydrionis computed, on the method that produced them, or on the compilation itself. The underlying measurements remain the publishers’ and their attribution requirements apply to you directly.

Recommended, not required. Hydrionis does not claim rights over unmodified public data it relayed, and doing arithmetic on somebody else’s measurements does not make them Hydrionis’s. Cite the version and the access date: the Upper Missouri-Dearborn gauge records changes as publishers release and as methods are revised, and a citation without both cannot be checked later. Full guidance is on cite and reuse.

None of the contributing licences requires attribution. Crediting the publishers is still good practice and they are listed above.

Where these figures come from

MeasuredHigh confidence2025-05-20

Source: USGS — National Water Information System, USGS site 06090800, annual peak streamflow. Licence: Open.

Method: The instantaneous maximum discharge of each water year as published by USGS, dated to the day it occurred. One value per October-to-September water year; where the publisher lists both a systematic and a historic peak for a year, the larger is the annual maximum. Values the publisher marks as maximum daily averages are not held here, because they are not instantaneous peaks. Values marked as bounded rather than measured are held as censored observations carrying the bound. Cubic feet per second are converted to cubic metres per second and the publisher unit is recorded alongside.

Rating curves are extrapolated at extreme discharges, so the largest values in a peak series carry the largest measurement uncertainty. Data from the U.S. Geological Survey National Water Information System, a work of the United States government and therefore in the public domain.

Retrieved 1 October 2026.