The monitoring network within this area

Hydrionis holds 1,451 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.

2

Gauges

1,451

Values held

1928–2026

Record spans

Gauges within the South Fork Salmon 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 JOHNSON CREEK AT YELLOW PINE ID

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1929–2025.

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	JOHNSON CREEK AT YELLOW PINE ID (m³/s)
1929	62.3
1930	56.1
1931	41.1
1932	90.6
1933	146
1934	59.5
1935	68.5
1936	97.1
1937	48.7
1938	99.7
1939	58.6
1940	82.4
1941	71.4
1942	71.4
1943	96.0
1944	41.6
1945	68.8
1946	69.9
1947	128
1948	131
1949	131
1950	90.6
1951	85.5
1952	79.3
1953	104
1954	118
1955	83.0
1956	154
1957	119
1958	121
1959	81.6
1960	72.5
1961	89.8
1962	77.0
1963	96.6
1964	88.1
1965	123
1966	50.4
1967	90.0
1968	58.0
1969	90.6
1970	115
1971	107
1972	128
1973	59.7
1974	176
1975	83.8
1976	73.9
1977	17.9
1978	87.5
1979	65.1
1980	74.8
1981	76.2
1982	127
1983	125
1984	108
1985	62.6
1986	125
1987	44.7
1988	43.3
1989	60.9
1990	53.5
1991	58.3
1992	48.1
1993	95.1
1994	43.3
1995	84.1
1996	129
1997	125
1998	57.8
1999	111
2000	58.9
2001	43.9
2002	70.8
2003	127
2004	47.3
2005	84.7
2006	130
2007	51.3
2008	177
2009	130
2010	172
2011	97.1
2012	107
2013	94.3
2014	99.1
2015	37.1
2016	85.8
2017	143
2018	99.7
2019	88.6
2020	74.8
2021	47.0
2022	95.7
2023	105
2024	74.8
2025	90.0

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	1929–2025
Completeness	100.0% of the periods in that span are held.
Continuity	Continuous: every year from 1929 to 2025 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 JOHNSON CREEK AT YELLOW PINE ID, as a depth

The year's flow spread over the land draining to this gauge, in millimetres — the same unit rainfall is measured in. 1929–2024.

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	JOHNSON CREEK AT YELLOW PINE ID (mm)
1929	357
1930	452
1931	253
1932	575
1933	501
1934	441
1935	437
1936	506
1937	343
1938	642
1939	372
1940	514
1941	504
1942	514
1943	767
1944	328
1945	421
1946	629
1947	661
1948	638
1949	589
1950	689
1951	661
1952	632
1953	595
1954	628
1955	458
1956	836
1957	646
1958	617
1959	552
1960	461
1961	480
1962	607
1963	622
1964	525
1965	859
1966	369
1967	579
1968	419
1969	604
1970	635
1971	818
1972	666
1973	368
1974	960
1975	563
1976	627
1977	207
1978	658
1979	337
1980	592
1981	574
1982	819
1983	725
1984	652
1985	421
1986	630
1987	257
1988	295
1989	419
1990	391
1991	354
1992	327
1993	570
1994	271
1995	719
1996	816
1997	891
1998	564
1999	633
2000	460
2001	220
2002	432
2003	513
2004	432
2005	396
2006	648
2007	413
2008	638
2009	599
2010	537
2011	738
2012	697
2013	499
2014	616
2015	412
2016	578
2017	1,046
2018	614
2019	597
2020	522
2021	360
2022	567
2023	539
2024	496

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	1929–2024
Completeness	100.0% of the periods in that span are held.
Continuity	Continuous: every year from 1929 to 2024 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

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.

1,344

Fullest snowpack recorded at Big Creek Summit, in 1982 (mm of water)

428

Thinnest, in 2001 (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 Big Creek Summit

Water years 1982–2026. 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	Big Creek Summit (mm)
1982	1,344
1983	1,170
1984	853
1985	773
1986	1,067
1987	491
1988	508
1989	877
1990	538
1991	628
1992	652
1993	1,021
1994	509
1995	942
1996	900
1997	1,142
1998	815
1999	1,159
2000	747
2001	428
2002	731
2003	886
2004	733
2005	547
2006	1,162
2007	620
2008	896
2009	715
2010	599
2011	1,028
2012	835
2013	547
2014	813
2015	471
2016	769
2017	942
2018	759
2019	792
2020	742
2021	713
2022	606
2023	854
2024	628
2025	890
2026	507

Read against the river

Big Creek Summit and JOHNSON CREEK AT YELLOW PINE ID both sit in this drainage area, and their records overlap by 43 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 South Fork Salmon and what each holds
Gauge	Measures	Values	Record
JOHNSON CREEK AT YELLOW PINE ID	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	327	1928–2026
EF OF SF SALMON RIVER AT STIBNITE, ID	catchment area, annual maximum river flow	45	1929–2026

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 — 17060208. 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
JOHNSON CREEK AT YELLOW PINE ID	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
EF OF SF SALMON RIVER AT STIBNITE, ID	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	1	no
Years spanned	99	yes, 20 or more
Values held	1,451	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-13313000.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), South Fork Salmon gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-south-fork-salmon/

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 South Fork Salmon 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 confidence2025-05-11

Source: USGS — National Water Information System, USGS site 13313000, 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.