Nephosthe weather behind the paintings
Albert Bierstadt, The Rocky Mountains, Lander’s Peak: snow peaks under a bright sky above a waterfall, a lake and a Shoshone encampment.
The Metropolitan Museum of Art, 07.123, Rogers Fund, 1907. Public domain.

A study against the weather record

Albert Bierstadt

The Rocky Mountains, Lander’s Peak

1863 · The Metropolitan Museum of Art, 07.123

A critic called its sky “minutely authentic”. What was the summer Bierstadt sketched it actually like?

1.96inches of rain at Fort Bridger in July 1859, the wettest July the nearest gauge ever recorded.

“Minutely authentic” unknown“Constant rains” partially agrees

The recordsThe painting at the Met

The Nephos method

How this study was read

The method in full
  1. What is written

    Painted in New York and finished early in 1863, from sketches made in the Wind River country with Lander’s road survey in the summer of 1859.

  2. Records of those days

    Not found or not yet searched

    • No instrument stood in the Wind River Range or at the camp on the Green River in 1859.
    • No sketch from the trip is dated to the day. A second Bierstadt letter, in the New Bedford Daily Mercury of 14 September 1859, has not been read.
    • Bierstadt’s printed leaflet for visitors, which claimed firsthand observation, is known here only through a later catalogue’s summary.
  3. Each claim tested

    • “minutely authentic”: the painting’s fair sky, which Tuckerman describes as “a pure, blue sky”. At Fort Bridger, June 1859 was the warmest June on its record and nearly rainless, so fair days were common when the party reached South Pass on 24 June. July was the wettest July on its record: 1.96 inches on 13 days, with 17 cloudy days.
    • “mingling with the clouds”, Bierstadt’s own description of the summits, written on 10 July. Rain fell at Fort Bridger on every day from 7 to 12 July, 0.92 inches in all, including the day the letter is dated. The summits themselves were never observed.
    • “constant rains”, and the Green River “higher than ever known before”, in Lander’s report. The fort’s July rain is the highest of 26 complete Julys, 1858 to 1890, and nearly twice the modern normal. The river’s height was not measured.
    • The day and the place painted. The canvas was composed in New York three and a half years later; even the peak is disputed (Frémont Peak or Temple Peak).
  4. Verdict

    The fort’s record bears out the reports of a wet summer and also shows fair days; it cannot test an undated sky composed in the studio.

    • Unknown“minutely authentic” sky The register includes 14 fair days in July, but a remote gauge cannot test the authenticity of an undated, studio-composed sky.
    • Partially agrees“constant rains” The nearest gauge had its wettest July on record, but it stood more than 180 km from the peaks, and the river’s height was not measured.
    • UnknownThe day painted A studio composition from undated sketches; no day can be picked.

What this cannot tell you. Fort Bridger is 184 to 211 km from the candidate peaks and about 6,000 feet below them; mountain storms are local. The 1859 temperatures are readings at 7, 14 and 21 hours, not daily highs and lows, and cannot be set against modern averages. A clear morning between storms is entirely possible, so no single painted sky can be called false.

Step 2 · Records of those days

Sixty-one days at Fort Bridger

No instrument stood in the Wind River Range in 1859. The nearest was the post surgeon’s register at Fort Bridger, in the same Green River basin, 184 to 211 km from the peaks the painting may show and about 6,000 feet below them. The surgeon measured rain and read a thermometer at 7 a.m., 2 p.m. and 9 p.m. Each bar is one day’s rain; no day is missing.

Daily rain at Fort Bridger, 1 June to 31 July 1859One bar per day. June had 0.04 inches on 1 day; July had 1.96 inches on 13 days, with rain on every day from 7 to 12 July.0.20.40.60.8inchesJune 18591 June 1859: no rain2 June 1859: no rain3 June 1859: no rain4 June 1859: no rain5 June 1859: no rain6 June 1859: no rain7 June 1859: no rain8 June 1859: no rain9 June 1859: no rain10 June 1859: no rain11 June 1859: no rain12 June 1859: no rain13 June 1859: no rain14 June 1859: no rain15 June 1859: no rain16 June 1859: no rain17 June 1859: no rain18 June 1859: no rain19 June 1859: no rain20 June 1859: no rain21 June 1859: no rain22 June 1859: no rain23 June 1859: no rain24 June 1859: no rain25 June 1859: no rain26 June 1859: 0.04 in27 June 1859: no rain28 June 1859: no rain29 June 1859: no rain30 June 1859: no rainJuly 18591 July 1859: no rain2 July 1859: no rain3 July 1859: no rain4 July 1859: 0.03 in5 July 1859: no rain6 July 1859: no rain7 July 1859: 0.21 in8 July 1859: 0.13 in9 July 1859: 0.24 in10 July 1859: 0.27 in11 July 1859: 0.03 in12 July 1859: 0.04 in13 July 1859: no rain14 July 1859: no rain15 July 1859: no rain16 July 1859: no rain17 July 1859: no rain18 July 1859: no rain19 July 1859: 0.77 in20 July 1859: no rain21 July 1859: 0.05 in22 July 1859: 0.07 in23 July 1859: no rain24 July 1859: 0.06 in25 July 1859: 0.02 in26 July 1859: no rain27 July 1859: no rain28 July 1859: 0.04 in29 July 1859: no rain30 July 1859: no rain31 July 1859: no rain24 June: Lander’s party at South Pass10 July: Bierstadt dates his letter19 July, 0.77 in
Fort Bridger daily register, keyed by NOAA’s Climate Database Modernization Program and checked by the Midwestern Regional Climate Center. A thin mark under the line is a day with no rain.
1.96
inches of rain in July 1859, on 13 days
17
cloudy days that July in the Army’s printed register
0.92
inches from 7 to 12 July, rain every day
0.04
inches in all of June
Printed Army register for July 1859, Fort Bridger row: mean temperatures 65.12, 77.45 and 60.64; 14 fair days, 17 cloudy; 13 days of rain, 1.96 inches.
The Army’s own printed register for July 1859, published in 1860. Its Fort Bridger row, 14 fair days, 17 cloudy, 13 of rain and 1.96 inches, matches the daily file to the hundredth of an inch.
Every day, rain and the three thermometer readings
1859Rain, in7 a.m., °F2 p.m., °F9 p.m., °F
1 June0.00416143
2 June0.00467662
3 June0.00538157
4 June0.00658052
5 June0.00608260
6 June0.00677751
7 June0.00567450
8 June0.00547455
9 June0.00577560
10 June0.00578155
11 June0.00658052
12 June0.00677763
13 June0.00596852
14 June0.00537352
15 June0.00617555
16 June0.00708458
17 June0.00758359
18 June0.00738457
19 June0.00738959
20 June0.00748356
21 June0.00657962
22 June0.00628358
23 June0.00618161
24 June0.00707759
25 June0.00667961
26 June0.04557763
27 June0.00648261
28 June0.00688158
29 June0.00639065
30 June0.00698760
1 July0.00688458
2 July0.00679067
3 July0.00688868
4 July0.03798462
5 July0.00737161
6 July0.00638559
7 July0.21628762
8 July0.13686952
9 July0.24638961
10 July0.27626755
11 July0.03656655
12 July0.04597159
13 July0.00697959
14 July0.00668260
15 July0.00728460
16 July0.00708058
17 July0.00648258
18 July0.00648274
19 July0.77727962
20 July0.00626664
21 July0.05617361
22 July0.07647458
23 July0.00617862
24 July0.06596056
25 July0.02586959
26 July0.00658263
27 July0.00617960
28 July0.04666861
29 July0.00667862
30 July0.00658366
31 July0.00577759

Step 3 · The claims tested

1859 against every July on record

July 1859 is the wettest of the 26 Julys the fort recorded day by day between 1858 and 1890; the next is 1860, with 1.80 inches. A normal July at Mountain View, 7 km from the old fort, now brings 1.10. June had been the opposite: 0.04 inches, and the warmest of 21 Junes by the mean of the three daily readings.

July rain at Fort Bridger in every July recorded day by day, 1858 to 1890Each dot is one July. 1859 had 1.96 inches, the most of 26; the next was 1860, 1.80. A normal July today, 7 km away, brings 1.10.0.51.01.52.01860186518701875188018851890a normal July today, 1991–2020, 1.10 in1858: 0.14 in1860: 1.80 in1861: 0.36 in1863: 0.60 in1864: 0.20 in1865: 0.83 in1867: 0.18 in1868: 0.62 in1869: 0.41 in1870: 0.24 in1871: 1.04 in1872: 0.74 in1873: 0.95 in1874: 1.00 in1875: 0.56 in1876: 0.86 in1877: 0.28 in1881: 0.65 in1882: 0.32 in1883: 0.16 in1884: 0.50 in1885: 0.22 in1886: 0.00 in1889: 0.21 in1890: 0.06 in1859: 1.96 in1859: 1.96 in
Only Julys with a rain entry on all 31 days are shown. Modern normal: NOAA NCEI, 1991–2020.

“their jagged summits, covered with snow and mingling with the clouds, present a scene which every lover of landscape would gaze upon with unqualified delight.”

Bierstadt, letter dated Rocky Mountains, 10 July 1859, The Crayon, p. 287

“We are about to turn our faces homeward again, the season being a short one here, and to avoid the fall deluge on the plains, which renders the roads almost impassable.”

The same letter

“The season has been an unusual one; the mountain streams swollen by constant rains, and Green river higher than ever known before in the memory of the oldest mountaineers.”

F. W. Lander, report to Congress, 1 March 1860, p. 3

Step 4 · Why the verdict stops at the season

The picture was made in New York

Bierstadt finished the canvas early in 1863, three and a half years after the trip, from sketches, oil studies and stereographs. Tuckerman praised the truth of its sky; Jarves, writing in the same years, judged that such pictures got the details right and the whole wrong. A gauge more than 180 km away cannot say that any one painted sky was false, only that fair weather was not the whole of that summer.

“Sky, atmosphere, and foliage, are all, in hue and character, minutely authentic.”

Henry T. Tuckerman, Book of the Artists, 1867, p. 396

“Far above and away, the snow-clad peaks rising into a pure, blue sky, and flecked with sun-tinted vapor”

The same, p. 395

“With singular inconsistency of mind they idealize in composition and materialize in execution, so that, though the details of the scenery are substantially correct, the scene as a whole often is false.”

James Jackson Jarves, The Art-Idea, on Church and Bierstadt, 1866 printing, p. 234

Sources

Every source on this page

Each file was downloaded and given a fingerprint (its sha256). The page is rebuilt from these files and will not build if a fingerprint changes, so every number above comes from them rather than being typed in.

  1. Fort Bridger daily register, 1858–1890: NOAA Climate Database Modernization Program, keyed and checked by the Midwestern Regional Climate CenterNOAA data; MRCC asks to be credited · retrieved 29 September 2026 · station 483430, microfilm reel AE06169sha256 c7e99251275e0bc1b6e401f597ff0a86d2048a378b6da040ee923b5d43b9356e
  2. Fort Bridger station metadata (MRCC)NOAA data; MRCC asks to be credited · retrieved 29 September 2026sha256 58c637069bc34fca313c6b39e6f54c8ef6eed6994c35889efc9faa8fb151d582
  3. Statistical Report on the Sickness and Mortality in the Army of the United States, 1855–1860 (Washington, 1860): Meteorological Register, July 1859U.S. government work; National Library of Medicine scan · retrieved 29 September 2026 · p. 441, Fort Bridger rowsha256 15f7d5f74d75fb49106f9f2b1d20763ab5b937faa570bcfc0e65ac91cd75414a
  4. NOAA NCEI 1991–2020 monthly normals, Mountain View, Wyoming (USC00486555)U.S. government work · retrieved 29 September 2026sha256 b736e2690594214a9ec96125970ba761cadd0fefc114391dc3f4ca5dd083954a
  5. The Crayon, vol. 6, September 1859, “Sketchings”1859 text in the public domain; JSTOR Early Journal Content scan · retrieved 29 September 2026 · p. 287, letter dated Rocky Mountains, July 10, 1859sha256 05393689c88998eab884d40ea3e1765b58d1b75f9e93f4a50198d7ec83497ab9
  6. F. W. Lander and others, Fort Kearney, South Pass and Honey Lake wagon road, report of 1 March 1860 (U.S. Serial Set 1100)U.S. government work · retrieved 29 September 2026 · p. 3sha256 3876b95fbd02fee85d7ef416942274bf377848147ec004486425fa02fd0632c5
  7. Henry T. Tuckerman, Book of the Artists (1867), p. 396Public domain; Internet Archive scan · retrieved 29 September 2026sha256 c9fe367b75d6f32abfabe2cc3d51f56e510caa1748d5bf15016a14d91973a443
  8. Henry T. Tuckerman, Book of the Artists (1867), p. 395Public domain; Internet Archive scan · retrieved 29 September 2026sha256 12552a1981bf2582ce4dbfe3ce09898f05510df02e5c0aa6dbf192ba5fb92d2c
  9. James Jackson Jarves, The Art-Idea (1866 printing), p. 234Public domain; Internet Archive scan · retrieved 29 September 2026sha256 56b7b8298426892f1c65df18ab94dbf7fe3a6d38b2e7191f6d65f6b7d4e4efab
  10. The Metropolitan Museum of Art, The Rocky Mountains, Lander’s Peak, 07.123 (Open Access record)Public domain image (Met Open Access) · retrieved 29 September 2026sha256 becad0be297a732e0956d9f0b982f77ba850511c9797eff9f7d8ab24bccf0541

The numbers on this page, as JSONThe method card, as JSON