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Handbook of Yosemite National Park (1921)
by Ansel F. Hall

ContentsPrevious: Photography in Yosemite



By Ansel F. Hall

One often reads praises and generalities about Yosemite climate and weather but, so far as the writer knows, no concise statement as to exactly what might be expected at any given time of year has ever been published. The accompanying table has been compiled from the U. S. Weather Bureau daily records for the past eleven years and the data summarized for each month. By examining this table one may determine with fair accuracy the conditions which will be encountered at the time of his visit. The following remarks, however, should be borne in mind.

Temperature. The Mean Maximum is the average of the hottest temperatures for each day during the month (generally about 2 p.m.). The Mean Minimum is the average of the coldest temperatures for each night during the month (generally about 3 a.m.). The Mean Temperature is the average temperature for the entire month. The Maximum Temperature is the hottest recorded temperature during the month and the Minimum the coldest recorded during the same period. The Greatest Daily Range is the greatest temperature change for any twenty-four-hour period during the month. The Mean Maximum and the Mean Temperature show very little variation between the different years, but the Mean Minimum varies considerably, especially in the late spring and summer months. The Greatest Daily Ranges for the different months fluctuate greatly in different years, sometimes as much as fifteen degrees, so this factor in the table is not as reliable for forecasting temperatures as are the other averages.

Precipitation. Rainfall is a factor which varies extremely in different years in both amount and frequency. The frequency is indicated in the horizontal column headed "Number of Days with .01 inch or more Precipitation"; it must be remembered in this connection that from May to October on days upon which rain does fall it is generally as short thunder showers.

Snowfall. Snowfall is the one climatic factor which shows the most variation from year to year. A light snowfall sometimes occurs in October and may be rather definitely expected in November, the first snow in five of the past eleven years having occurred during the latter month; during these two months the snow generally melts quickly. In December, however, one may reasonably expect permanent snow, for the records show that in all but three of the past eleven years Yosemite Valley has had a "white Christmas." The melting of the permanent snow is more definite and may be expected quite regularly between March 15th and 30th.

Clear Days. The number of clear, partly cloudy, and cloudy days per month is surprisingly the same from year to year and these figures in the table will closely approximate actual conditions for any month.


MONTHLY SUMMARYJan.Feb.Mar.Apr.MayJuneJulyAug.Sept.Oct.Nov.Dec.Average
Mean MaximumDegrees F.
Mean Minimum"21.223.827.432.736.742.948.547.241.228.725.421.033.1
Mean"32.737.444.251.255.564.269.670. 163.653.241.833.451.4
Greatest Daily Range"36.042.348.351.351.452.253.756.055.656.446.539.049.1
Greatest in 24 hours"1.941.431.18.701.
Total snowfallInches33.158.518.73.6Trace.
On ground 15th"
On ground 30th"10.413.2TraceTrace.
Number of Days per Month
With .01 in. or more precip.
Partly cloudy8.


Lake.Species of Trout.Fishing.
Adair LakeGolden Trout, 1919?
Arndt LakeNoneNo fish
Babcock LakeRainbow (Date unknown),
Steelhead, 1919
Bearup LakeLoch Leven (Date unknown)Fair
Benson LakeSpecies unknown, 1897
Loch Leven, 1905
Rainbow, 1905
Bernice LakeEastern Brook, 1917
Loch Leven, 1913
Branigan LakeRainbow (Date unknown)Good
Breeze LakeLoch Leven, 1905
Eastern Brook, 1917
Rainbow, 1917
Buena Vista LakeEastern Brook, 1892, 1908, 1918, 1919
Rainbow, 1892
Cathedral LakeEastern Brook, 1897, 1915Poor
Chain o’ Lakes (near
Fernandez Pass) (3)
Dolly Varden, (Date unknown)Good
Chiquito Lake1NoneNo fish
Crescent LakeEastern Brook, 1891, 1909, 1911Poor
Doe LakeNo fishNo fish
Dog LakeEastern Brook, 1907, 1915, 1917, 1918, 1919
Rainbow, 1920
Loch Leven, 1920
Dorothy LakeRainbow, 1911, 1913Fair
Echo LakeEastern Brook, 1913Fair
Edith LakeNoneNo fish
Edna LakeBrown Trout, 1905?
Eleanor LakeRainbow, 1878, 1880
Eastern Brook, 1908
Elizabeth LakeEastern Brook, 1907Good
Ellery Lake1?Good
Emeric LakeSteelhead, 1919Good
Emigrant Lake1Loch Leven (Date unknown)Good
Evelyn LakeLoch Leven, 1913
Rainbow, 1878, 1880
Eastern Brook, 1913
Fletcher LakeEastern Brook, 1897
Loch Leven, 1913
Flora LakeNoneNo fish
Gabriel LakeEastern Brook (Date unknown)No fish
Gaylor Lakes (5)Rainbow, 1906
Cutthroat (Date unknown)
Givens LakeEastern Brook (Date unknown)No fish
Grant Lakes (2)Easter Brook, 1918
Steelhead, 1918
Grouse LakeRainbow, 1917Good
Harden LakeNoneNo fish
Harriet LakeNoneNo fish
Helen Lake (Near
Mt. Starr King)
NoneNo fish
Helen Lake (Near Kuna
NoneNo fish
Hidden LakeNoneNo fish
Huckleberry Lake1Loch Leven (Date unknown)Good
Ireland LakeEastern Brook, 1897Excellent
Irwin LakeRainbow, 1912Fair
Johnson LakeRainbow, 1897
Eastern Brook, 1891, 1911, 1917, 1919
Kibbie LakeRainbow, 1878, 1880Good
Laurel LakeEastern Brook (Date unknown)
Rainbow (Date unknown)
Lillian LakeRainbow (Date unknown)Fair
Lost LakeNoneNo fish
Lukens LakeNoneNo fish
Mary LakeRainbow, 1911Fair
Mattie LakeNoneNo fish
May LakeEastern Brook, 1908, 1917
Loch Leven, 1908
Rainbow, 1908, 1913
McCabe Lakes (5)Loch Leven, 1920?
McGee LakeRainbow, 1913
Eastern Brook, 1916, 1917
Merced LakeBrown Trout, 1905
Loch Leven, 1905, 1918
Species unknown, 1908
Mildred LakeSpecies and date unknownGood
Miller LakeSpecies unknown, 1911?
Minnow LakeEastern Brook, 1897Good
Murdock LakeNoneNo fish
Neall LakeSpecies and date unknownGood
Onion LakeNoneNo fish
Ostrander LakeRainbow, 1892, 1893, 1899, 1911
Eastern Brook, 1893, 1899
Cutthroat (Date unknown)
Peeler Lake1CutthroatExcellent
Rock Island LakeNoneNo fish
Rodgers LakeRainbow, 1907
Loch Leven, 1907
Royal Arch LakeEastern Brook, 1897Excellent
Rutherford Lake1Rainbow (Date unknown)
Eastern Brook, 1905
Saddlebag Lake1Species and date unknownGood
Shamrock LakeNoneNo fish
Sister LakeNoneNo fish
Smedberg LakeNo recordPoor
Snow LakeNoneNo fish
Soldier LakeNoneNo fish
Spiller LakeSpecies unknown, 1875Poor
Summit Lake1Species and date unknownPoor
Surprise LakeNoneNo fish
Swamp Lake (Near McGill
NoneNo fish
Swamp Lake (Near
Gravelly Ford
NoneNo fish
Table LakeNoneNo fish
Tallulah LakeNoneNo fish
Tenaya LakeEastern Brook, 1909, 1917, 1918, 1919, 1920
Rainbow, 1911, 1915, 1917, 1918, 1919, 1920
Loch Leven, 1911, 1920
Cutthroat, 1918, 1919
Steelhead, 1919
Ten Lakes (10)Eastern Brook, 1908, 1913, 1915, 1918
Loch Leven, 1908
Steelhead, 1918
Tilden LakeSpecies unknown, 1905, 1911
Rainbow, 1912
Tioga Lake1Species and date unknownGood
Twin LakesSpecies and date unknown?
Vernon LakeRainbow, 1878, 1880
Eastern Brook (Date unknown)
Virginia LakeRainbow (Date unknown)Fair
Virginia Lakes1Species and date unknownGood
Vogelsang LakeLoch Leven, 1913
Eastern Brook, 1918
Washburn LakeEastern Brook, 1905
Loch Leven, 1905
Species unknown, 1908
Wilmer LakeRainbow (Date unknown)
Eastern Brook (Date unknown)
Young LakeEastern Brook, 1914
Rainbow, 1914
Unnamed chain of Lakes
near Lake Eleanor (4)
Loch Leven, 1911?
Unnamed lake 1 mi. west of
Parsons Peak
Loch Leven, 1913?
Unnamed lake at the
source of Emeric Creek
Cutthroat, 1919
Golden, 1920
Unnamed lakes just
west of Schofield Peak
Rainbow. 1912?
Unnamed lake near
Vogelsang Pass
Eastern Brook, 1918No fishing
Unnamed lakes (2) near
Bernice Lake
Eastern Brook, 1917Good

1 = Outside park boundaries.

Besides the lakes listed above (112 in the Park and 10 just outside) the U. S. G. S. "Topographic Map of Yosemite National Park" shows 317 other unnamed lakes—mostly small—within the Park. The total number of lakes within the Park is 429.


Stream.Species of Trout.Fishing.
Alder CreekEastern Brook, 1891
Loch Leven, 1897
Rainbow (Date unknown)
Fish plentiful
but small
Alkali CreekNoneNo fishing
Avalanche CreekNoneNo fishing
Babcock CreekRainbow, 1896
Eastern Brook, 1905
Big CreekSpecies unknown, 1905?
Big Meadow CreekNoneNo fishing
Bishop CreekRainbow, 1896Poor
Bluejay CreekNoneNo fishing
Breeze CreekRainbow, 1896Good
Bridalveil CreekRainbow, 1892, 1899, 1905
Eastern Brook, 1893, 1899
Buck CreekNoneNo fishing
Budd CreekNoneNo fishing
Buena Vista CreekRainbow (Date unknown)Good
Camp CreekNoneNo fishing
Cascade CreekEastern Brook, 1897Fish all small
Cathedral CreekEastern Brook, 1917
Rainbow, 1920
Plentiful but
Cherry Creek1Species and date unknownGood
Chilnualna CreekEastern Brook, 1892, 1899
Rainbow, 1892, 1899
Fish plentiful
but small
Conness CreekRainbow (Date unknown)Fair
Crane CreekRainbow, 1915, 1916, 1917 Fish all small
Dana Fork Tuolumne RRainbow (Date unknown)Good
Delaney CreekRainbow (Date unknown)Poor
Dingley CreekRainbow (Date unknown)Poor
Eagle Peak CreekNoneNo fish
Echo CreekEastern Brook, 1905---
Eleanor CreekSpecies and date unknownGood
Falls CreekRainbow, 1913Good
Fletcher CreekE. Brook (Date unknown)Good
Florence Creek??
Foerster CreekNoneNo fish
Frog CreekRainbow, 1905Good
Givens CreekNoneNo fish
Gray CreekNoneNo fish
Grouse CreekRainbow (Date unknown)Good
Illilouette Creek, near mouthCutthroat, 1918Good
Illilouette Creek, above
Valley rim
Eastern Brook, 1893
Rainbow, 1893, 1905
Illilouette Creek, Clark ForkRainbow, 1905Good
Indian Creek, near ChinquapinRainbow (Date unknown)Fair
Indian Creek, Indian CanyonNoneNo fish
Ireland CreekNoneNo fish
Jack Main CreekRainbow, 11905Good
Kerrick CreekSpecies unknown, 1905
Rainbow, 1906
Kibbie CreekNoneNo fishing
Leevining Creek1Species and date unknownGood
Lilly CreekNoneNo fishing
Little Crane CreekSpecies and date unknownFair
Little YosemiteEastern Brook, 1891, 1905
Rainbow, 1891, 1896, 1911, 1912, 1913, 1917
Lyell Fork, Merced R.Eastern Brook, 1908
Rainbow, 1908
Lyell Fork, Tuolumne RiverEastern Brook, 1879, 1919
Rainbow, 1896, 1915
Cutthroat, 1896
Tahoe Trout, 1896
Matterhorn CreekEastern Brook, 1905Good
Merced River,
  at El Portal
Eastern Brook, 1918, 1919Good
  at Yosemite ValleyRainbow, 1909, 1912, 1917
Brown Trout, 1905, 11920
Loch Leven, 1912
Dolly Varden (Date unknown)
Steelhead, 1917
Cutthroat, 1918, 1919
Eastern Brook, 1917, 1918, 1919, 1920
  at Little YosemiteEastern Brook, 1891, 1905
Rainbow, 1891, 1896, 1911, 1912, 1913, 1917
Merced River, McClure ForkEastern Brook, 1905Good
Merced River, Lyell ForkRainbow, 1908
Eastern Brook, 1908
Merced River, South ForkRainbow (Date unknown)
Brown Trout (Date unknown)
Eastern Brook, 1899
  at Gravelly FordCutthroat, 1895Good
  near Buck CampEastern Brook, 1899
Rainbow, 1899
Miller CreekEastern Brook, 1916Good
Moss CreekRainbow, 1915
Eastern Brook (Date unknown)
Fish plentiful
but small
Murphy CreekSpecies and date unknownFair
North Crane CreekSpecies and date unknownFish all small
Ottoway CreekNoneNo fish
Pigeon CreekNoneNo fish
Piute CreekRainbow, 1896
Eastern Brook, 1903, 1905
Porcupine CreekSpecies unknown, 1897Fish all small
Rafferty CreekNoneNo fishing
Rancheria CreekEastern Brook, 1905Good
Red CreekNoneNo fish
Register CreekNoneNo fish
Return CreekEastern Brook, 1896, 1913Poor
Ribbon CreekNoneNo fish
Rodgers Canyon Cr.Rainbow (Date unknown)Good
Rush Creek (Merced)Rainbow, 1892, 1897
Unknown, 1905
Sentinel CreekNoneNo fishing
Slide Canyon Cr.NoneNo fishing
Smith CreekEastern Brook, 1916Fish all small
Snow CreekSpecies and date unknownFish all small
Spiller CreekNoneNo fishing
Stubblefield Canyon Cr.NoneNo fishing
Sunrise CreekSpecies and date unknownPoor
Tamarack CreekEastern Brook, 1896, 1920
Rainbow or Cutthroat, 1919
Fish all small
Tenaya Creek in Yosemite
Eastern Brook, 1907
Rainbow, 1909
Thompson Canyon Cr.NoneNo fish
Tilden Canyon Cr.Species and date unknownGood
Tiltill CreekSpecies unknown, 1897
Eastern Brook, 1905
Tripple CreekEastern Brook. 1907Good
Tuolumne River
  at Hetch Hetchy
Tahoe Trout, 1896
Cutthroat, 1896
Rainbow, 1896, 1906
Eastern Brook, 1906
  at Conness CreekCutthroat, 1896Good
  at Soda SpringsTahoe, 1895
Loch Leven, 1920
Rainbow. 1896, 1915, 1920
Tuolumne River, Lyell
Tahoe, 1896
Rainbow, 1896, 1915
Eastern Brook, 1897, 1899, 1919
Cutthroat, 1896
Tuolumne River, Dana
Rainbow (Date not known)Good
Tuolumne River, Middle
Loch Leven, 1897
Eastern Brook, 1906, 1917, 1918, 1919
Tuolumne River, South
Species unknown, 1905
Rainbow, 1899
Eastern Brook, 1906, 1917, 1918, 919
Virginia Canyon Cr.Loch Leven, 1920
Rainbow, 1920
Wilson CreekEastern Brook, 1916?
Yosemite CreekEastern Brook, 1893, 1897, 1917
Rainbow, 1893, 1905
Cutthroat, 1897

1 = Outside park boundaries.


In using the following key the trees are eliminated by groups until the species is finally determined. For example: We may first examine the leaves to determine whether they are in bundles or arranged singly on the branchlets; this will eliminate the large group "I" or "II." If the tree falls in group "I" we then determine whether there are 5, 3, 2, or 1 needles in a sheath; this will put the tree in class "A," "B," "C," or "D." If the species falls in class "A" it may be further traced by comparing the characteristics listed under subdivisions "1," "2," and "3"; these will determine the species.


(All have needle-like, awl-like, or scale-like leaves)

I.—Leaves in bundles with a sheath around the base (Pines)

A—Needles in bundles of 5 (White Pines)

1—Cone large (12 to 24 in.). Bark red-brown, in large plates, and flaky. Alt. 4000 to 7000.

SUGAR PINE . . . Pinus lambertiana

2—Cone medium (6 to 10 in.). Bark dark gray and in small 5-sided plates. Alt. 7500 to 9500.

WESTERN WHITE PINE . . . Pinus monticola

3—Cone small (about the size of a hen’s egg) and hard. Bark white and smooth. Alt. 9000 to 11,000.

WHITE BARK PINE . . . Pinus albicaulis

B—Needles in bundles of 3 (Yellow pines)

1—Foliage silver-gray. Small or medium-size tree, generally branching into several main trunks. Cones large (5 to 8 in.), heavy, and armed with stout hooks. Alt. only below 3000.

DIGGER PINE . . . Pinus sabiniana

2—Foliage green. Tree large and generally with but one main trunk. Bark in large plates and flaky. Alt. 2000 to 8000.

(a)—Cones 2 1/2 to 5 1/2 in. long. Foliage green. Bark yellow-brown.

WESTERN YELLOW PINE . . . Pinus ponderosa

(b)—Cones 5 1/2 to 11 in. long. Foliage blue-green. Bark reddish brown. Generally at higher altitudes than western yellow pine.

JEFFREY PINE . . . Pinus jeffreyi

C—Needles in bundles of 2. Cones small (3/4 to 2 1/2 in.). Small tree (average 70 ft. tall and 2 ft. in dia.). Bark purple-gray and in flakes (not plates).

LODGEPOLE PINE OR "TAMARACK" . . . Pinus contorta

D—Needles one in a sheath. Cones small (2 to 3 in.) but seeds large. Tree small. Occurs entirely on eastern slope of Sierra Nevada except one tree in Pate Valley.

PINYON OR NUT PINE . . . Pinus monophylla

II.—Leaves not in bundles.

A—Leaves linear (i.e., needle-like.) Bark never fibrous or stringy.

1—Fruit a cone.

(a)—Cones erect and occur only near tops of trees. Leaves without petioles (leaf stalks). (Firs)

I—Bark of old trees gray and deeply furrowed. Needles on lower branches spread flat (2-ranked). Alt. 4000 to 8000.

WHITE FIR . . . Abies concolor

II—Bark of old trees red and roughened by vertical and transverse fissures. Needles all around branchlets and curved up. Alt. above 7000.

RED FIR . . . Abies magnifica

(b)—Cones pendent. Leaves with petioles.

I—Cone medium sized (2 to 4 in.) and with trident-shaped bracts sticking from between the scales. Tip of tree erect. Alt. 3000 to 6000.

DOUGLAS FIR . . . Pseudotsuga taxifolia

II—Cone small (i in.) and without exserted bracts. Tip of tree drooping. Alt. only above 8500.

MOUNTAIN HEMLOCK . . . Tsuga mertensiana

2—Fruit a drupe (like a plum) with a kernel much like a nutmeg when dried. Needles sharp-pointed and two-ranked. Small tree occurring in the canyon of the Merced only below Cascade Falls.

CALIFORNIA NUTMEG . . . Tumion californicum

B—Leaves scale-like or awl-like. Bark of all older trees fibrous and stringy.

1—Fruit a blue berry (really a modified cone). Leaves scale-like and closely pressed around twigs. Spray round. Inhabits open rocky sites above 7000 ft. alt.

WESTERN JUNIPER . . . Juniperus occidentalis

2—Fruit a true cone.

(a)—Cones medium size (1 1/2 to 3 in.) and with many scales. Needles of lower branches awl-like. Mature trees very large. Occurs only in scattered groves, the nearest of which is 17 1/2 miles from Yosemite.

GIANT SEQUOIA . . . Sequoia gigantea

(b)—Cones small (i inch or less) and with only 5 (apparently 3) scales. Needles scale-like and decurrent (i.e., with a portion of their bases fastened along the branchlets). Trees up to 5 feet in diameter. Spray flattened. Occurs abundantly in Yosemite Valley and up to 8000 ft. alt.

INCENSE CEDAR . . . Libocedrus decurrens

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