The monitoring network within this area

Hydrionis holds 2,279 values from 5 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.

5

Gauges

2,279

Values held

1904–2026

Record spans

Gauges within the Middle North Platte-Casper huc8 subbasin

5 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 LA PRELE CREEK NEAR DOUGLAS, WY

The highest instantaneous discharge the publisher recorded in each year — a flood peak as measured, not a daily average of one. 1920–1992.

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 (0 events)

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	LA PRELE CREEK NEAR DOUGLAS, WY (m³/s)
1920	122
1921	16.1
1922	20.2
1923	21.3
1924	19.4
1925	19.5
1926	21.2
1927	25.4
1928	18.6
1929	20.3
1930	13.5
1931	5.21
1932	10.4
1933	28.3
1934	1.93
1935	19.1
1936	8.21
1937	18.8
1938	25.1
1939	14.3
1940	6.12
1941	26.0
1942	23.8
1943	5.07
1944	28.3
1945	25.1
1946	26.1
1947	27.9
1948	9.71
1949	16.9
1950	11.1
1951	18.0
1952	45.9
1953	13.9
1954	3.00
1955	10.5
1956	3.51
1957	17.7
1958	6.68
1959	9.34
1960	5.72
1961	6.31
1962	28.9
1963	28.0
1964	24.6
1965	207
1966	5.07
1967	23.4
1968	19.0
1969	7.48
1970	490
1971	97.4
1972	20.5
1973	48.7
1974	16.6
1975	8.10
1976	13.8
1977	12.8
1978	48.1
1979	3.99
1980	17.8
1981	13.1
1982	14.6
1983	85.0
1984	37.9
1985	1.56
1986	83.0
1987	4.84
1988	12.9
1989	1.87
1990	4.45
1991	53.8
1992	1.22

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	1920–1992
Completeness	100.0% of the periods in that span are held.
Continuity	Continuous: every year from 1920 to 1992 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 NORTH PLATTE RIVER AT ALCOVA, WY, as a depth

The year's flow spread over the land draining to this gauge, in millimetres — the same unit rainfall is measured in. 1905–1997.

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 (0 events)

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	NORTH PLATTE RIVER AT ALCOVA, WY (mm)
1905	54.0
1935	31.0
1936	45.0
1937	47.0
1938	44.0
1939	44.0
1940	25.0
1941	32.0
1942	36.0
1943	44.0
1944	40.0
1945	34.0
1946	40.0
1947	30.0
1948	44.0
1949	39.0
1950	47.0
1951	41.0
1952	61.0
1953	39.0
1954	28.0
1955	23.0
1956	39.0
1957	33.0
1958	59.0
1959	38.0
1960	35.0
1961	28.0
1962	33.0
1963	44.0
1964	38.0
1965	30.0
1966	47.0
1967	27.0
1968	39.0
1969	45.0
1970	27.0
1971	49.0
1972	43.0
1973	69.0
1974	68.0
1975	49.0
1976	43.0
1977	40.0
1978	36.0
1979	44.0
1980	53.0
1981	39.0
1982	34.0
1983	69.0
1984	85.0
1985	63.0
1986	64.0
1987	36.0
1988	42.0
1989	38.0
1990	28.0
1991	30.0
1992	30.0
1993	29.0
1994	43.0
1995	22.0
1996	48.0
1997	60.0

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	Derived Computed by Hydrionis
Period held	1905–1997
Completeness	68.8% of the periods in that span are held. Gaps are drawn as breaks and never interpolated.
Known gaps	One period inside 1905–1997 holds no value: 1906 to 1934, 29 years with no reading. It is drawn as a break in the line and is never interpolated across.
Continuity	The record begins in 1905 and is not continuous from it: 93 years separate the first value from the last, and 69% 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

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

669

Fullest snowpack recorded at Casper Mtn., in 1983 (mm of water)

84

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 Casper Mtn.

Water years 1983–2026. 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	Casper Mtn. (mm)
1983	669
1984	602
1985	345
1986	486
1987	405
1988	449
1989	200
1990	277
1991	465
1992	336
1993	576
1994	434
1995	640
1996	355
1997	619
1998	323
1999	349
2000	393
2001	311
2002	221
2003	354
2004	287
2005	259
2006	384
2007	295
2008	371
2009	358
2010	417
2011	307
2012	441
2013	292
2014	470
2015	205
2016	442
2017	279
2018	203
2019	371
2020	408
2021	338
2022	302
2023	368
2024	259
2025	210
2026	84.0

Why the snow is not read against the river here

These two series do not overlap in time: Peak snow water equivalent runs 1982–2026 and Mean river flow, water year runs 1905–1959.

Every gauge Hydrionis holds within this area

Gauges within the Middle North Platte-Casper and what each holds
Gauge	Measures	Values	Record
NORTH PLATTE RIVER AT ALCOVA, WY	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	231	1904–2026
LA PRELE CREEK NEAR DOUGLAS, WY	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	213	1919–2026
NORTH PLATTE RIVER BELOW PATHFINDER RESERVOIR, WY	burned area within 50 km, catchment area, annual maximum river flow, mean river flow, mean river flow, water year	166	1905–2026
BOX ELDER CREEK NEAR CAREYHURST, WY	catchment area, annual maximum river flow	43	1928–2026
LA PRELE CREEK NEAR ORPHA, WY	catchment area, annual maximum river flow	42	1924–2026

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 — 10180007. 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
NORTH PLATTE RIVER AT ALCOVA, WY	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
LA PRELE CREEK NEAR DOUGLAS, WY	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
NORTH PLATTE RIVER BELOW PATHFINDER RESERVOIR, WY	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
BOX ELDER CREEK NEAR CAREYHURST, WY	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
LA PRELE CREEK NEAR ORPHA, WY	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	123	yes, 20 or more
Values held	2,279	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-06642000.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), Middle North Platte-Casper gauge records, accessed 2026-10-05, hydrionis.com/waters/united-states-middle-north-platte-casper/

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 Middle North Platte-Casper 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 confidence1997-10-06

Source: USGS — National Water Information System, USGS site 06642000, 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.