The monitoring network within this area

Hydrionis holds 2,321 values from 6 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.

6

Gauges

2,321

Values held

1890–2026

Record spans

Gauges within the Upper Missouri huc8 subbasin

6 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 Tenmile Creek near Rimini MT

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1915–2024.

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	Tenmile Creek near Rimini MT (m³/s)
1915	13.3
1916	8.38
1917	22.1
1918	4.87
1919	2.27
1920	8.47
1921	10.6
1922	10.9
1923	4.90
1924	10.4
1925	4.90
1926	5.66
1927	19.9
1928	7.05
1929	11.3
1930	5.07
1931	1.16
1932	5.52
1933	7.31
1934	4.05
1935	2.29
1936	1.87
1937	3.79
1938	13.9
1939	3.85
1940	2.72
1941	5.92
1942	6.85
1943	8.41
1944	7.16
1945	6.54
1946	2.07
1947	9.57
1948	11.4
1949	3.03
1950	9.03
1951	8.18
1952	6.85
1953	13.3
1954	3.14
1955	4.11
1956	6.20
1957	4.11
1958	6.12
1959	5.72
1960	7.76
1961	5.27
1962	6.29
1963	4.30
1964	15.9
1965	6.97
1966	4.02
1967	9.06
1968	7.87
1969	8.72
1970	6.17
1971	5.01
1972	5.78
1973	3.11
1974	6.23
1975	28.2
1976	10.7
1977	0.821
1978	6.71
1979	6.63
1980	5.89
1981	93.2
1982	7.14
1983	7.16
1984	6.34
1985	3.14
1986	5.72
1987	4.11
1988	3.74
1989	5.21
1990	3.82
1991	4.84
1992	5.15
1993	5.61
1994	5.47
1997	8.66
1998	6.29
1999	6.06
2000	0.821
2001	3.48
2002	3.77
2003	5.47
2004	2.07
2005	6.43
2006	5.72
2007	3.34
2008	6.00
2009	9.46
2010	9.15
2011	21.0
2012	5.64
2013	3.06
2014	7.90
2015	5.27
2016	3.94
2017	3.71
2018	23.0
2019	6.97
2020	8.10
2021	3.43
2022	5.95
2024	2.77

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	1915–2024
Completeness	97.3% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	2 separate periods inside 1915–2024 hold no value. The longest runs from 1995 to 1996 — 2 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1915 and is not continuous from it: 110 years separate the first value from the last, and 97% 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 Tenmile Creek near Rimini 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. 1915–2024.

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	Tenmile Creek near Rimini MT (mm)
1915	352
1916	413
1917	555
1918	232
1919	95.0
1920	285
1921	305
1922	262
1923	164
1924	159
1925	192
1926	200
1927	395
1928	171
1929	189
1930	121
1931	36.0
1932	106
1933	145
1934	88.0
1935	60.0
1936	53.0
1937	75.0
1938	253
1939	120
1940	81.0
1941	99.0
1942	193
1943	266
1944	199
1945	188
1946	90.0
1947	255
1948	287
1949	129
1950	278
1951	248
1952	142
1953	251
1954	79.0
1955	160
1956	116
1957	102
1958	165
1959	136
1960	163
1961	76.0
1962	173
1963	176
1964	246
1965	234
1966	104
1967	242
1968	173
1969	195
1970	162
1971	122
1972	127
1973	42.0
1974	151
1975	428
1976	282
1977	38.0
1978	192
1979	126
1980	232
1981	358
1982	243
1983	202
1984	178
1985	104
1986	190
1987	125
1988	83.0
1989	146
1990	167
1991	124
1992	47.0
1993	182
1998	173
1999	120
2000	18.0
2001	86.0
2002	111
2003	133
2004	82.0
2005	185
2006	123
2007	117
2008	178
2009	253
2010	286
2011	420
2012	159
2013	123
2014	276
2015	162
2016	155
2017	139
2018	441
2019	235
2020	225
2021	107
2022	145
2023	311
2024	109

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	Derived Computed by Hydrionis
Period held	1915–2024
Completeness	96.4% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	One period inside 1915–2024 holds no value: 1994 to 1997, 4 years with no reading. It is drawn as a break in the line and is never interpolated across.
Continuity	The record begins in 1915 and is not continuous from it: 110 years separate the first value from the last, and 96% of the years between them are held. The span is not the record.
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

The snow standing above this water

2 automated snow stations sit inside this drainage area, weighing the snowpack rather than measuring how deep it is.

442

Fullest snowpack recorded at Frohner Meadow, in 1975 (mm of water)

118

Thinnest, in 2026 (mm of water)

April

Month the pack is usually at its fullest

June

Month the pack has gone by, in half of years

Peak snowpack at Frohner Meadow

Water years 1973–2026. Each point is the fullest month of that snow season.

A water year runs October to September and is named for the year it ends, so the snow of one winter stays in one point. The value is the fullest month, not the fullest day: a pack that peaked sharply mid-month reads lower here than a single measurement taken at the right moment would.

View the data behind this chart

Underlying data
Period	Frohner Meadow (mm)
1973	222
1974	271
1975	442
1976	229
1977	131
1978	247
1979	281
1980	244
1981	216
1982	308
1983	222
1984	214
1985	191
1986	194
1987	137
1988	154
1989	204
1990	186
1991	222
1992	154
1993	175
1994	156
1995	148
1996	201
1997	268
1998	167
1999	171
2000	144
2001	206
2002	164
2003	218
2004	167
2005	187
2006	202
2007	161
2008	204
2009	238
2010	152
2011	256
2012	237
2013	159
2014	323
2015	158
2016	165
2017	187
2018	358
2019	230
2020	185
2021	182
2022	162
2023	249
2024	121
2025	161
2026	118

Read against the river

Frohner Meadow and Tenmile Creek near Helena MT both sit in this drainage area, and their records overlap by 51 years. That is the span the two have in common, not a count of years both actually hold — either record may have gaps inside it. The two are shown separately rather than on one axis: millimetres of stored water and cubic metres per second are not commensurable, and a difference between them would mean nothing.

Being in the same drainage area does not put the snowpack upstream of the gauge. A subbasin is an area, and snow on one tributary can join the river below a gauge on another — so a weak relationship here may say more about which tributary was measured than about the snow.

Every gauge Hydrionis holds within this area

Gauges within the Upper Missouri and what each holds
Gauge	Measures	Values	Record
Tenmile Creek near Rimini MT	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	356	1914–2026
Missouri River at Toston MT	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	307	1890–2026
Prickly Pear Creek near Clancy MT	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	282	1908–2026
Tenmile Creek near Helena MT	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	211	1908–2026
Missouri River bl Hauser Dam near Helena MT	catchment area, annual maximum river flow	38	1923–2026
Crow Creek near Radersburg MT	catchment area, annual maximum river flow	23	1901–2026

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 — 10030101. 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
Tenmile Creek near Rimini 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 Toston 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
Prickly Pear Creek near Clancy 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
Tenmile Creek near Helena 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 bl Hauser Dam near Helena 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
Crow Creek near Radersburg 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 5 of them, which makes it a full profile.

Information-gain signals held for this water body
Signal	Held	Counts
Gauges holding a real record	4	yes, 3 or more
Years spanned	137	yes, 20 or more
Values held	2,321	yes, 1000 or more
Distinct measurements	6	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-06062500.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 gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-upper-missouri/

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 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 confidence2024-05-29

Source: USGS — National Water Information System, USGS site 06062500, 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.