The monitoring network within this area

Hydrionis holds 3,550 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

3,550

Values held

1889–2026

Record spans

Gauges within the Gallatin 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 Gallatin River at Logan MT

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1895–2025.

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	Gallatin River at Logan MT (m³/s)
1895	115
1896	185
1897	183
1898	207
1899	279
1900	137
1902	125
1903	127
1904	153
1905	87.5
1929	141
1930	79.9
1931	84.1
1932	129
1933	105
1935	113
1936	124
1937	103
1938	158
1939	79.0
1940	99.1
1941	56.4
1942	168
1943	174
1944	136
1945	99.1
1946	106
1947	174
1948	223
1949	110
1950	112
1951	117
1952	188
1953	168
1954	95.7
1955	115
1956	204
1957	141
1958	103
1959	173
1960	122
1961	61.2
1962	137
1963	135
1964	178
1965	173
1966	98.0
1967	197
1968	206
1969	147
1970	266
1971	240
1972	145
1973	157
1974	260
1975	220
1976	189
1977	74.2
1978	141
1979	122
1980	129
1981	209
1982	203
1983	181
1984	200
1985	105
1987	59.5
1988	113
1989	106
1990	124
1991	230
1992	122
1993	182
1994	96.6
1995	204
1996	207
1997	266
1998	178
1999	159
2000	111
2001	73.9
2002	158
2003	165
2004	105
2005	115
2006	142
2007	105
2008	178
2009	158
2010	173
2011	226
2012	141
2013	114
2014	188
2015	128
2016	112
2017	130
2018	204
2019	159
2020	182
2021	134
2022	246
2023	159
2024	155
2025	127

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	1895–2025
Completeness	80.2% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	4 separate periods inside 1895–2025 hold no value. The longest runs from 1906 to 1928 — 23 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1895 and is not continuous from it: 131 years separate the first value from the last, and 80% 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 Gallatin River at Logan 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. 1894–2024.

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	Gallatin River at Logan MT (mm)
1894	221
1895	204
1896	209
1897	214
1898	235
1899	251
1900	201
1901	192
1902	173
1903	195
1904	222
1905	135
1929	178
1930	146
1931	123
1932	167
1933	145
1934	72.0
1935	113
1936	121
1937	120
1938	176
1939	142
1940	159
1941	143
1942	210
1943	241
1944	189
1945	179
1946	191
1947	255
1948	280
1949	185
1950	195
1951	189
1952	268
1953	188
1954	148
1955	163
1956	203
1957	185
1958	164
1959	221
1960	195
1961	140
1962	249
1963	213
1964	239
1965	288
1966	162
1967	255
1968	308
1969	278
1970	311
1971	303
1972	226
1973	231
1974	278
1975	330
1976	312
1977	164
1978	250
1979	203
1980	219
1981	252
1982	305
1983	261
1984	297
1985	160
1986	226
1987	136
1988	153
1989	166
1990	182
1991	200
1992	161
1993	305
1994	147
1995	256
1996	238
1997	331
1998	250
1999	204
2000	149
2001	123
2002	146
2003	148
2004	127
2005	162
2006	184
2007	158
2008	246
2009	221
2010	221
2011	306
2012	175
2013	145
2014	221
2015	159
2016	169
2017	195
2018	280
2019	228
2020	205
2021	141
2022	186
2024	186

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	1894–2024
Completeness	81.7% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	2 separate periods inside 1894–2024 hold no value. The longest runs from 1906 to 1928 — 23 years with no reading. They are drawn as breaks in the line and are never interpolated across.
Continuity	The record begins in 1894 and is not continuous from it: 131 years separate the first value from the last, and 82% 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

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

598

Fullest snowpack recorded at Lick Creek, in 1970 (mm of water)

123

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 Lick Creek

Water years 1964–2026. 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	Lick Creek (mm)
1964	486
1965	432
1966	227
1967	479
1968	451
1969	214
1970	598
1971	545
1972	274
1973	474
1974	426
1975	577
1976	428
1977	396
1978	257
1979	326
1980	336
1981	275
1982	395
1983	334
1984	342
1985	275
1986	218
1987	208
1988	317
1989	266
1990	286
1991	375
1992	219
1993	258
1994	214
1995	344
1996	270
1997	442
1998	275
1999	294
2000	255
2001	243
2002	211
2003	316
2004	238
2005	231
2006	225
2007	285
2008	327
2009	329
2010	237
2011	387
2012	261
2013	270
2014	441
2015	196
2016	242
2017	161
2018	365
2019	254
2020	343
2021	282
2022	248
2023	356
2024	184
2025	304
2026	123

Read against the river

Lick Creek and Gallatin River near Gallatin Gateway, MT both sit in this drainage area, and their records overlap by 61 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 Gallatin and what each holds
Gauge	Measures	Values	Record
Gallatin River at Logan MT	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	357	1893–2026
Gallatin River near Gallatin Gateway, MT	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	318	1889–2026
Hyalite C at Hyalite R S nr Bozeman MT	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	249	1895–2026

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 — 10020008. 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
Gallatin River at Logan 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
Gallatin River near Gallatin Gateway, 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
Hyalite C at Hyalite R S nr Bozeman 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	3	yes, 3 or more
Years spanned	138	yes, 20 or more
Values held	3,550	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-06052500.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), Gallatin gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-gallatin/

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 Gallatin 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 confidence2025-06-02

Source: USGS — National Water Information System, USGS site 06052500, 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.