The monitoring network within this area

Hydrionis holds 4,577 values from 3 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.

3

Gauges

4,577

Values held

1921–2026

Record spans

Gauges within the Clarks Fork Yellowstone huc8 subbasin

3 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 Clarks Fork Yellowstone River nr Belfry MT

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1922–2022.

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	Clarks Fork Yellowstone River nr Belfry MT (m³/s)
1922	227
1923	197
1924	151
1925	246
1926	157
1927	283
1928	309
1929	166
1930	166
1931	174
1932	235
1933	219
1934	130
1935	240
1936	275
1937	240
1938	283
1939	164
1940	152
1941	138
1942	216
1943	278
1944	203
1945	228
1946	176
1947	176
1948	252
1949	208
1950	213
1951	229
1952	235
1953	250
1954	236
1955	161
1956	249
1957	286
1958	206
1959	274
1960	176
1961	197
1962	193
1963	223
1964	204
1965	244
1966	183
1967	276
1968	221
1969	168
1970	242
1971	289
1972	292
1973	209
1974	297
1975	360
1976	218
1977	170
1978	232
1979	229
1980	243
1981	419
1982	278
1983	183
1984	191
1985	186
1986	265
1987	123
1988	174
1989	212
1990	188
1991	253
1992	162
1993	187
1994	158
1995	280
1996	323
1997	309
1998	161
1999	230
2000	185
2001	140
2002	317
2003	314
2004	178
2005	201
2006	195
2007	158
2008	272
2009	270
2010	286
2011	354
2012	292
2013	190
2014	331
2015	235
2016	195
2017	320
2018	334
2019	286
2020	379
2021	247
2022	671

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	1922–2022
Completeness	100.0% of the periods in that span are held.
Continuity	Continuous: every year from 1922 to 2022 is held.
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 Clarks Fork Yellowstone River nr Belfry 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. 1922–2024.

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	Clarks Fork Yellowstone River nr Belfry MT (mm)
1922	241
1923	272
1924	271
1925	406
1926	284
1927	414
1928	422
1929	261
1930	262
1931	176
1932	268
1933	218
1934	227
1935	260
1936	293
1937	227
1938	272
1939	222
1940	208
1941	238
1942	242
1943	418
1944	246
1945	299
1946	256
1947	253
1948	277
1949	272
1950	350
1951	362
1952	275
1953	247
1954	280
1955	203
1956	335
1957	337
1958	237
1959	310
1960	190
1961	228
1962	294
1963	280
1964	285
1965	362
1966	214
1967	370
1968	278
1969	243
1970	314
1971	394
1972	374
1973	232
1974	365
1975	360
1976	378
1977	156
1978	322
1979	260
1980	294
1981	278
1982	328
1983	251
1984	275
1985	182
1986	302
1987	171
1988	165
1989	271
1990	250
1991	267
1992	269
1993	249
1994	192
1995	301
1996	402
1997	451
1998	262
1999	302
2000	238
2001	166
2002	278
2003	267
2004	209
2005	217
2006	228
2007	201
2008	349
2009	346
2010	224
2011	424
2012	290
2013	241
2014	440
2015	262
2017	431
2018	524
2019	357
2020	307
2021	219
2022	326
2023	300
2024	236

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	1922–2024
Completeness	99.0% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	One period inside 1922–2024 holds no value: 2016. It is drawn as a break in the line and is never interpolated across.
Continuity	The record begins in 1922 and is not continuous from it: 103 years separate the first value from the last, and 99% 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

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

1,459

Fullest snowpack recorded at Fisher Creek, in 1971 (mm of water)

544

Thinnest, in 2001 (mm of water)

April

Month the pack is usually at its fullest

July

Month the pack has gone by, in half of years

Peak snowpack at Fisher Creek

Water years 1967–2026. 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	Fisher Creek (mm)
1967	1,327
1968	911
1969	904
1970	1,055
1971	1,459
1972	1,355
1973	759
1974	1,445
1975	1,184
1976	1,203
1977	608
1978	1,113
1979	960
1980	832
1981	657
1982	1,172
1983	813
1984	833
1985	741
1986	974
1987	584
1988	751
1989	1,032
1990	917
1991	869
1992	752
1993	752
1994	697
1995	957
1996	1,287
1997	1,441
1998	760
1999	1,098
2000	831
2001	544
2002	942
2003	1,007
2004	714
2005	662
2006	1,070
2007	799
2008	1,173
2009	1,003
2010	663
2011	1,339
2012	1,008
2013	792
2014	1,161
2015	768
2016	712
2017	1,206
2018	1,413
2019	891
2020	870
2021	753
2022	840
2023	903
2024	625
2025	783
2026	969

Read against the river

Fisher Creek and Clarks Fork Yellowstone River nr Belfry MT both sit in this drainage area, and their records overlap by 57 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 Clarks Fork Yellowstone and what each holds
Gauge	Measures	Values	Record
Clarks Fork Yellowstone River nr Belfry MT	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	342	1921–2026
Clarks Fork Yellowstone River at Edgar MT	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	295	1921–2026
Rock Creek at Rockvale MT	catchment area, annual maximum river flow	18	1921–2026

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 — 10070006. 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
Clarks Fork Yellowstone River nr Belfry 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
Clarks Fork Yellowstone River at Edgar 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
Rock Creek at Rockvale 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 4 of them, which makes it a full profile.

Information-gain signals held for this water body
Signal	Held	Counts
Gauges holding a real record	2	no
Years spanned	106	yes, 20 or more
Values held	4,577	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-06207500.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), Clarks Fork Yellowstone gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-clarks-fork-yellowstone/

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 Clarks Fork Yellowstone 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 confidence2022-06-13

Source: USGS — National Water Information System, USGS site 06207500, 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.