ProfessiOnal Paper No. 19 Senes 0, Systematic Geology and Paleontology, 64 

DEPARTMENT OF THE INTERIOR 

UNITED STATES GEOLOGICAL SURVEY 

CHAHLES D WALCOTT, DIRE<-TOR 

CoNTRIBUTIONS T·o THE GEoLOGY oF WASHINGTON 

Geology and Physiography of Central Washington 

By GEORGE OTIS SMITE-I 

Physiography and Deformation of the Wenatchee-Chelan District 

Cascade Range 

By BAILEY WILLIS 

W ASIIING'l'ON 

GOVl<~RNMl<~NT PHINTING Ol!'J<'ICE 

1903 

CONTRIBUTIONS TO THE GEOLOGY OF WASHINGTON 

GEOLOGY AND PHYSIOGRAPHY OF CENTRAL WASHINGTON 

HY 

GEORGE OTIS SJYIITH 

-~---- ====-----====---==---====- --

" •> 

CONTENTS. 

Page 

In trod uctton ........................................ . 9 

Ltterat.ue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . 10 

Geology ..... : .......................................................... _ ............. _. 13 

Formatwn~ ........... _ . __ .... _ .................. _ ................. _. _ .. _.. . . . . . . . . 13 

Pte-Eocene..................................................................... 14 

Ea~ton schtst ........... _. __ .......... _ ........ _ .................. _ ... · ... __ . 1-1 

Peshastm formatwn ................. _ . _ ... _ ........... _ ................ _.... 14 

Hawktns formatiOn ... _ .......... _ .. _. _. _ .. ____ . _ ........... _ ....... _ ...... _ 14 

Igneous rol'ks.................. .......... ...................... .......... 14 

Eocene .............................. _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • 15 

Swank formatwn...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 

Teanaway basalt.......................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . _... 15 

Roslyn formatwn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 

.Manastash formatwn ..................................................... _.. 16 

1\-Iwcene and later ... __ . . . . . . __ .... __ ................ _ ......... _ ... __ .... __ .... 16 

Y aktma basalt . _ •.......... _ ....................... _. _ ...... _ .............. _ 16 

Ellensburg formatwn. . . ... _ ........................... -,.. . . . . . . . . . . . . . . . . . . 17 

Later lavas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 

Pletstocene depostts ...................................................... __ . 19 

Structure ............................................. -............................. 19 

::\iount Stuart qua<lrangle .... _.......................... . . . . . . . . . . . . . . . . . . . . . . . . 19 

Ellensburg quadrangle ....................................................... _... 21 

Htstory (s_ummary) ................................................................. 21 

Phystography ......................... _ ........................................... ------ 22 

TopographiC desert phons .............................. _..... . . . . . . . . . . . . . . . . . . . . . . • . 22 

::\iount Stuart 'regwn. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 

Y aktma reg10n.............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • . • . 23 

Cas<'ade lowland . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • . . . . . 24 

Idenhficatton ........................................... l. . . . . . . . . . . . . . . . . . . . . . . 24 

Development ....... :. . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 

Cascade plateau. . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 

Character of the uphft................................. . . . .. . . . . . . . . . . . . . . . . . . . . 29 

Varying degree ot dulsection..................................................... 30 

River htstory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . 32 

Physwgrapby of the Snoqualn11e quadrangle......... . . . . . . . . . . . . . . . . . . . . . . . . . . :l4 

Resume . . . . . . . . . . . . . . • . . . . . . . . . . . . . . . • . .. . . . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 38 

5 

IltUSTRATIONS. 

Page. PLATE 1 Map ol C'entral W ash~ngton _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 10 

II Yak1ma Canyon at Beavertail Bend_---- ________________ ------ __ ----------______ 12 

III GeologiC map of a portwn of the Mount Stuart quadrangle.__________________ _ _ _ _ 14 

IV Geolog1c map of a portwn of the Ellensburg quadrangle _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 18 

V. Physwgrapluc sketC'h map of a portion of the Ellensbmg quadrangle_ ..•. _ .. ______ 26 

VI. Map of Yak1ma Canyon, w1th geologic sectwn _- __ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 32 

VII. Map of Snoquahme quadrangle ___ ---- _----- ---------- _ - 36 

Fw I Contact ol Ellensburg sandstone and Yak1ma baRalt _________________ . _ _ _ _ _ _ _ _ _ _ _ _ _ 27 

7 

GEOLOGY AND PHYSIOGRAPHY OF CENTRAL WASHINGTON. 

By GEORGE OTIS SMITH. 

INTRODUCTION. 

Central Washington includes a part of two great topographic provinces; the 

great plain of the Columbia and~ the Cascade Range. The former, in 1ts position 

and general desert-like character, suggests at once a resemblance to the Great Basin 

of Utah and Nevada; and the vastness of the desert plam is emphasized by the snowy 

peakfl of the Ca;,cades along its western border. These provinces are not to be 

regarded as unconnected in their geologic history, however great the contrast in 

their general features. The intermediate zone between the great plain on the ea10,t 

and the mountain range on the west is a strategic point for the investigation of the 

geologic ;,tructure and history and the interpretation of the present topograph}r of 

hoth provinces. On the extensive basalt-covered plain monotony wearies the 

traveler, while on the rocky peaks of the Cascades the complexity taxes the powers 

of the observer. 

Yakima River, an 1mportant tnbutary of the Columbia, drains a large area on 

the ea;,tern slope of the Cascade Mountains, and in the medial portion of its coun,e 

this nver traverses a region which shares many of the features belonging to the 

two provinces mentioned above. The Mount Stuart and Ellensburg quadranglesa 

are situated close to the geographic center of the State' of ·washington and mclude 

an area of about 1,600 square mile:; In the southern portion of this area the country 

i:; characterized by broad valleys and low, gently sloping ridges. The general absence 

of fore;,t trees and the abundance of the sagebrush are other features that remind 

the traveler of the great pla~n to the east. In the northern part of the Mount Stuart 

quadrangle the ndges arc of a bolder type and the extremely rugged topography of 

Mount Stuart and other portions of the Vv enatchee Mountams suggests at once the 

mam range of the Cascades. These two quadrangles have been surveyed both topographically and geologically, and the results of these surveys constitute the basis of 

the present paper. 

a Under the plan adopted b~ thi~ •urvey for the preparatwn of a geologiC map of the Umted States the entue area IS 

diVIded mto small quadrangles, bounded by eertam meridians and parallels, and each " named from ~ome well-known 

place or feature appearmg III 1t 
10 CONTRIBUTIONS TO GEOLOGY OF WASHINGTON. 

In the preparation of this paper I have had the privilege of frequent conference 

with Mr. Hailey Willis. His familiarity with the area here described has given 

special value to his helpful criticism, which is gratefully acknowledged. Portions of 

the area described by Mr. Willis have also been visited by myself, and I believe the 

conclusions reached in his paper to be in general agreement with the results of the 

work in central Washington. The separation of the two areas and the fact that 

the :field work was more or less distinct and conducted u:qder different conditions led 

to the publication of our results as two papers, rather than as a joint contribution to 

the geology of the region. In the mapping of the Ellensburg quadrangle I was 

assisted by Mr. Frank C. Calkins. . 

· ?'he results of this survey have been published in the Ellensburg folio, No. 86, 

of the Geologic Atlas of the United States. 

:r ... ITERA.'.rURE. 

A glance at the literature whic~ is available regarding this area will serve to 

show the present state of our knowledge of the geology and physiography of central 

Washington. Russell a records the occurrence of older crystalline rocks in this area, 

separated by an unconformity from overlying sediments of early Tertiary age. Above 

these, with another unconformity, is the great series of lava flows, named by Russell 

the "Columbia lava," b above which is another sedimentary series of Miocene age, 

correlated by Russell with the John Day beds of Oregon. Professor Russell's dete-rmination of the age of the Cascade Range as post-Miocene" is provisional only, but 

the antecedent character. of the main streams of the region is more definitely stated, 

as follows:. 

"The evidence that the main drainage lines of central Washington were established before the present relief was initiated is cumulative and abundant. The rivers 

began to flow when Lake John Day was drained and had their courses determined by 

the slope of the surface of the bottom' of the old lake. Since then mountain ranges 

have been formed by faulting, but the larger streams, i.e., the Columbia and Yakima, 

were able to cut down their channels as rapidly as the ridges were upraised athwart 

their channels." d 

The structure of the range is thus described: 

"It seems probable that the Cascades are formed to a large extent of tilted 

blocks of basalt which were origmally horizontal, and belong to the same series as 

the Columbia [River] lavas farther east, which have been, in comparison, only 

moderately disturbed. The Cascade Mountains, at least in the State of Washington, 

do not seem to have been formed mainly by the piling up of erupted material, as has 

been suggested in explanation of their origin farther south, but are due to the 

a A geological reconnaissance in central Washington: Bull. U.S. Geol. Survey No. 108, pp. 20-25. 

bThi8 has later been termed by Russell the Columbia River Java. 

cJbid., p. 24. dlbid., p. 97. 
U . S . GEOLOGICAL SURVEY PROFESSIONAL PAPER NO.I9 PL. I 

MAP OF CENTRAL WASHINGTON ora inagt f~em u~~~rat&ite~aps 

Geological Survey 

CONTOURS ON RESTORED WARPED SURFACE OF 'fHE METHOW (PLIOCENE) PENEPLAIN 

Scale 

\!co,.=~==~====d'ob""'""'"""""'.l2~0=====~30mDell 1903 

.JULIUS BIEN & CO . L I)H . N .Y. 
LITERATURE. 11 

uplifting and tilting of previously consolidated lava sheets, as well as of granite and 

coal-bearing strata, which occur high up on each flank of the mountain, and even 

form portions of the main divide. The great volcanoes which appear so prominent 

along the general trend of the range are secondary to the main mountain building." a 

In a later publication b Professor Russell describes more fully the Columbia 

River lava, and states that its maximum thickness in the Snake River region is 

over 5,000 feet. c The geologic history of the whole of the Columbia Plains area is 

sketched.d In early Tertiary times there were mountains in what is now northern 

Washington and eastern Idaho, but the central and southern portions of the Cascades 

were not yet in existence. In the area now including the great plai.n of the Columbia 

sedimentation went on in early Tertiary times, clays and sand~ being deposited, with 

accumulations of vegetable matter later changed to coal. Upheaval of these sediments "brought these once level sheets of rock above the sea and raised them into a 

mountain range, the southern Cascade." Erosion followed this upheaval, and later 

came_ the eruptions of the basaltic lavas which were spread over thousands o,f square 

miles. Succeeding the volcanic outbursts came lacustral sedimentation ·in broad 

lakes, probably formed "by the upheaval of the Cascade Mountains." These 

. Miocene sediments are those which Professor Russell earlier called the John Day. 

Since the draining of the Miocene lakes Snake River has performed an immense 

task, having carved in the basalt plateau a gorge about 15 miles broad at the top 

and in plac-es about 4,000 feet deep. 

A later paper gives a fuller development of Professor Russell's e interpretation 

of the geologic hi&tory of the Cascade Range. The geologic formations are more 

fully described, mention being made of the older metamorphic schists, the igneous 

rocks, granite, greenstone, and serpentine, the sedimentary rocks of pre-Cretaceous, 

Cretaceous, and Tertiary age, and the Columbia River lava and volcanic rocks of 

Glacier Peak. On the subject of the structure of the northern Cascades Professor 

Russell says: "It will be seen that the structure of the range is highly complex, and 

is by no means a single great, north-south anticline, or a simple monoclinal block. 

sculptured by erosion." J Attention is also called to lateral folds and faults on the 

eastern side of the range in central Washington, and the age of these secondary 

disturbances is shown to be late Tertiary or post-Tertiary, and apparently 

contemporaneous "with the latest great upward movement in the Cascade Mountain 

mass." Again the author notes the antecedent character of the Columbia and 

Yakima, which cross in narrow gaps these "tilted blocks." The origin of the range 

a A geologiCal reconnaissance m central Washington· Bull U S. Geol. Survey No. 108, p 30. 

b A reconnaissance m southern Washington Water-Sup and lrr. PRper No. 4, U.S Geol Survey. 

olb1d, p. 42. d Ibid., pp, 88-93. 

e A prellmmary paper on the geology o! the Cascade Mountains in northern Washington· Twentieth Ann. Rept 

U.S. Geol <;urvey, pt 2. 

! Ibid. p 137. 
12 CONTRIBUTIONS TO GEOLOGY OF WASHINGTON. 

is thus stated: "The Cascade Mountains, as we know them, seem to have been carved 

from an upraised peneplain. This plain we term the Cascade peneplain; and the 

plateau may be conveniently det'lignated the Cascade plateau." a Russell's hypothesis 

of a Cascade peneplain rests upon the presence of truneated folds, stream erosion 

having reduced the whole region nearly to sea level. "During the later portion of 

the time of base-leveling, the widely spread sheets of Columbia [River] hwa were 

poured out. The date of the period of planation is shown approximately by the 

fact that fol'ded beds of Eocen~ age were truncated. The broad peneplain must 

therefore have reached its greatest degree of perfection in late Tertiary time, 

probably extending into the Pleistocene." b It will be noted that the epoch of great 

basalt eruptions is thus included in the period of reduction to base-level. 

In brief, Professor Russell's "conception of the origin of the larger topographic 

features of the northern Cascades is that the reg·ion, having a complex structure, 

was reduced by erosion to a condition of low relief, and at a later date than the folding 

of the Tertiary sediment:; and the outspreading of the Columbia [River] lava was 

broadly upraised about 7,500 feet in the axial region. The course:; of the larger 

streams were then established and the plateau was deeply dissected." e The author 

then describe:; the extent to which the dissection of the Cascade plateau has proceeded, 

and mentions in this connection the striking feature that the larger stream:; of central "r ashington, of which Yakima River is the best example, have carried the low grade 

far hack toward the axil'> of the mnge. d It is also noted that the courses of the 

streams are in a marked way independent of the structure of the uprai:;cd region.e 

In attempting to determi~e the position of the upraised peneplain surface, 

Professor Russell observes that no recognizable flat-topped remnants of the original 

plateau are to be found in the more elevated portions of the range, but that the 

sharp-crested ridges and acute peaks may testify to a general diminution in height 

in the case of the soft rocks, while the harder rocks, such as the granites, more 

nearly approximate the original elevation of the plateau. Such evidence thht the 

surface of the Cascade plateau ·has been somewhat lowered by erosion is not 

thought by Professor Russell to be conclusive.f 

In a later paper/7 Professor Russell goes into a discussion of the character of the 

plateau which was built up by the Columbia River lava. Taking as a premise the 

general parallelism of the succession of the lava flows as exposed in canyon walls, 

he argues that during the period of eruption there were no general movements such 

as would cause unconformities within the Columbia River series. This lava is 

a A preliminary paper on the geology of the Cascade Mountains m northern Washmgton: Twentieth Ann. Rept., 

U. S. Geol. Survey, pt.~ •. p, 140. 

b Ibid,. p. 144. c Ibid., p. 142. <t Ibid., p. 145. e Ibid., p. 150. f Ibid., p. 141. 

a The geology and water resources of Nez Perccs County, Idaho: Water-Sup. and Irr. Paper No. 54, U.S. Geol. Survey. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 19 PL. II 

YAKIMA CANYON AT BEAVERTAIL BEND. 
FORMATIONS. 13 

believed to have been poured out in a "series .of vast inundations over a deeply 

eroded land surface." Since the series is in places over 4,000 feet thick, if there was 

no substdence during the period of eruption the surface of the last flow must have 

had at ~east that elevation above the sea. That there were no movements producing 

a depression during the period of eruption is believed by Professor Russell on the 

grounds that there are no marine sediments interbedded with the lava sheets; and 

neither have unconformities been detected in the eastern portion of the area covered 

by the Columbia River lava. On this acqount the horizontal surface of the lava 

plateaus in eastern Washington and Oregon and the adjacent part of Idaho should 

have an elevation of at least 4,000 feet or more above the sea. On the contrary, the 

elevation of such plateaus is between 3,000 and 3,300 feet, and this difference of 

approximately 1,000 feet is supposed by Rusflell to indicate a general subsidence of 

the eastern portion of the lava region. In his discussion of the drainage of this area 

Professor Russell, however, still regards Snake River where it crosses the lava 

plateau as an antecedent stream. 

GEOLOGY. 

FORMATIONS. 

The two quadrangles which this paper chiefly describes contain rocks of various 

ages. The geologic section is fairly representative for the whole State, and its discussion is therefore of more than local interest. Pis. III and IV show the geology 

of characteristic portions of the two quadrangles. The separation of the older and 

the younger rocks is an obvious one, and would he noted by any close observer. In 

a general way it may be stated that within this area the oldest rocks lie to the north, 

in the vicinity of Mount Stuart, and the youngest to the south. To describe this 

section as a southward-dipping monodine, however, would be misleading, since 

this would disregard the many marked unconformities which separate the different 

formations. 

In this chapter the rocks will be grouped according to age as pre-Eocene, Eocene, 

and Mio"ccne and later. The first class includes rocks that are unfossiliferous and 

plainly more or less altered, with intrusive rocks predominating. Above the base 

of the Eocene .the rocks are fresher in appearance and contain fossil~ by which their 

exact age is determined, while the igneous rocks are chiefly surface volcanics. The 

Miocene rocks are so fresh appearing that in places it is difficult to distinguish them 

from recent deposits. Thus it will be f>een that the grouping adopted is a natural 

one. 

These formations are more fully described in the Ellensburg folio, No. 86, and 

the Mount Stuart folio, which i~ in the course of publication. 
14 CONTRIBUTIONS TO GEOLOGY Olf WASHINGTON. 

PRE-EOCENE. 

Easton schist.-This is probably the oldest rock to be found m central 

Washington. It is not shown upon either of the accompanying geologic maps, 

but occupies a few square miles in the southwestern part of the Mount ..Stuart 

quadrangle and extends westward into the Snoqualmie quadrangle. Here it forms 

In large part the ~outhern wall of the Yakima Valley, and is especially prominent 

southeast of the town of Easton. 

The Easton schist is typically a silver-gray or green rock, composed principally 

of quartz and micas. The schist is extremely crumpled and is gashed and seamed 

with veins and stringers of quartz. Associated with this quartz-mica rock are other 

schists, containing hornblende or epidote, while quartzite is also found. The 

occurrence of this quartzite in close association with the schists 1s believed to 

indicate the sedimentary origin of the schists. 

Pe.Yhastin fo:rmation.-South of the Mount Stuart massif occurs a series of 

sedimentary rocks that may rank next to the Easton schist in age. These are black 

slate, with grit or conglomerate, and bands of black chert and lenses of light-gray 

limestone interbedded with the slate. In places these rocks show metamorphism by 

the igneous rocks with which they are in contact, and nowhere in the many exposures of this formation have any traces of fossils been discovered. 

It seems plausible to assign this sedimentary formation to the Paleozoic, and it 

is -possible that it is of Carboniferous age. This age determination rests simply 

upon a general resemblance of the formation to the Carboniferous reeks of the 

Sierra Nevada and of British Columbia. Rocks also strikingly similar to the 

Peshastin formation are found in the Blue Mountains of Oregon and in the Okanogan 

Valley in northern Washington. 

Hawkins fm•mation.-This is a volcanic series of flow-breccias, tuffs, and 

amygdaloids. These rocks are dark colored, green, or purple, extremely altered, 

and everywhere exerting a marked influence upon the topography, rough slopes with 

ragged crests being characteristic of this formation. While composed la1:gely of 

secondary minerals, these lavas and tuffs preserve their original textures, and 

microscopic study shows that the rocks were originally composed of augite and 

plagioclase, with diabasic texture. The whole series undoubtedly represents surface 

lava flows with associated tuffs. The Hawkins and Peshastin formations have been 

intricately mingled by close folding, while 8ubsequent intrusions of igneous rock 

have also obscured relations. 

Igne&us roaks.-Surrounding the older rocks just described are great belts of 

serpentine. This rock is intrusive, and its extent within the Mount Stuart quadrangle is important, since it covers nearly 50 square miles. The serpentine is an 

altered phase of peridotite, the latter rock being found in. its original state at many 
GEOLOGICMAPOFAPOR'fiONOFMOUNTSTUARTQUADRANGLE 

Topography by G.E.Hyde WASHINGTON 

Scale 

Geology by Geor)\e Otis Smith ass1sted by G.C.Curtis 

-====Oj,.,..,.s===""=====2 MILES 

ContOUl' intervallOO feet 

JULIUS BIEN &CO.LlTH. N .Y. 

;. LEGEND 

SURFICIAL ROCKS 

SEDIMENTARY ROCKS 

EOCENE 

Ros. ion 

(scuulstoneartdslzale) Sw. on 

(santkton.c,shale,mzd congWmerate) 

PRE-EOCENE 

(CARBONIFEROUS?) 

Peshtlllllllltion (slafean.dgrit with liJne.stone lenses) 

IGNEOUS ROCKS 

POST·EOCEN E 

I, J Rhyolite 

EOCENE 

WIA 

Basalt dikes 

. METAMORPHIC 

~ ROCK 

st 
EOCENE. 15 

places in the area. No rock can -be more varied in color or in physical characters 

than is t4is serpentine. . It ranges fro~ bright red to light green in color' and forms 

bold crags with gigantic talus blocks below, or rounded hills covered with fine 

shingle resembling broken glass. 

The se1;pentine and older rocks in which it is intruded contain gold and copper 

veins. Locally stich veins have been found to be very rich, but the amount of lowgrade ore far exceeds these bonanzas. 

This serpentine is intrusive in the Peshastin and Hawkins formations, but is 

itself cut by dikes of light porphyritic· rock. These latter are doubtless connected 

with the great batholith which forms Mount Stuart. The rock of the batholith is a 

typical granodiorite, often containing quartz, but too basic to be called a granite. · 

It is a gray granular rock, quite granitic in appearance. Generally fresh and unaffected by surficial alteration, its constituent minerals can be seen to be white feldspar, black mica, and hornblende, with a few grains of quartz. The granodiorite is 

everywhere massive, but is jointed and sheeted, this feature giving rise to the spire 

and minaret details so characteristic of the crest line of Mount Stuart. Dikes of the 

granodiorite can be traced extending out into the serpentine, so that it is plainly the 

youngest of the pre-Eocene rocks. 

EOCENE. 

8wauk fmwuition.-The oldest of the four Eocene formations is the Swauk 

formation, a series of sandstone, conglomerate, and shale, measuring in places at 

least 5,000 feet in thickness. The age is definitely determined as early Eocene by 

the fossil flora, and the basal beds are seen to be separated by a great unconformity 

from the formations upon which they rest. The conglomerate beds are mostly in 

the lower part of the section and the basal conglomerates arc often peculiar in that 

the pebbles and bowlders are derived almost wholly from the rock upon which the 

conglomerate rests. Thus, the conglomerate may be composed of granodiorite 

bowlders in an arkose matrix or of serpentine blocks embedded in a sand of the 

same composition. The sandstone is for the mo·st part arkose in character, although 

to the east the sediment shows better sorting and is more quartzose. The shale is 

often quite carbonaceous and rich in fossil leaves. 

This formation is of economic importance from the gold veins it contains in the 

Swank Basin. Most of the gold, however, is found in placers, but the gravels have 

all been derived from the Swauk formation and the gold is coarse and has not been 

carried far from the parent ledge. 

Teanaway basalt.-Overlying the Swauk sandstone and separated from it by a 

slight unconformity is a volcanic formatiol). The Teanaway basaltic series comprises 

lava flows and interbedded tuffs. The basalt is black and very compact and makes a 
16 CONTRIBUTIONS TO GEOLOGY OF W.ASHINGTON. 

prominent rock. The tJlffS arc very irregular in their distribution and tqe thickness 

of the whole series varies within the area from thousands of feet to a few hundred. 

This basalt has been termed by Russell the lowest or first sheet of Columbia 

River lava, but its importance in the stratigraphy of the region seems to warrant a 

.more definite separation from the Miocene lava to be described later. The most 

striking feature of the Teanaway basalt is the occurrence of hundreds of dikes which 

cut through the underlying Swauk formation and connect with this surface flow. 

'Fhe opportunity is afforded for observing almost diagrammatically the evidence that 

these basalt flows were erupted through many fissures, and for the most part the 

eruption appeared to be unaccompanied by any disturbance of the underlying rocks. 

Rosl;ynformatim~.-This sedimentary formation overlies the basalt without any 

apparent structural break, hut also without any evidence of transitional sedimentation of interbedded sands and tuffs. A few pebbles of basalt in the. basal beds show 

that locally there may have been erosion of the lava before the sedimentary beds 

began to be deposited. The Roslyn formation contains sandstones and shales, resembling the earlier Eocene sediments somewhat. Carbonaceous material becomes more 

important in the upper portion of the formation, where there are sevem,l beds of 

coal. The Roslyn coal seam is of commercial importance, and excellent steam coal 

is mined in quantities that give the Roslyn mine the first place among the coal mines 

of Washington. 

J11anastasA formation:-So far as known this formation is limited to t~e southwestern part of the Mount Stuart quadrangle and the adjacent portion of the Snoqualmie quadrangle. It is a series of sandstone, shale, and conglomerate beds, containing some seams of carbonaceous material, mostly bone. Fossil plants from the 

shales determine the age of the formation as Upper Eocene, and it is therefore to be 

correlated with the Clarno formation of the John Day Basin. Although these beds 

are somewhat younger than the Roslyn for~ation, which occurs a few miles to the 

north, the Manastash rests directly upoQ the old Easton schist, and this relation is 

believed to indicate nondeposition of the earlier Eocene sedimentsin this area. 

MIOCENE AND LATER. 

Yakirna basalt.-This basalt of Miocene age covers a considerable area m the 

Mount Stuart quadrangle and the larger part of the Ellensburg quadrangle. It 

extends to the northeast, east, and south of· these quadrangles, and also forms a 

portion of the higher part of the raf!ge west of the Ellensburg quadrangle. The 

base of this great series of lava flows is exposed .at many points in the Mount 

Stuart quadrangle, and the lavas are h'er~ seen to rest unconformably upon the 

Eocene formations. This unconformity between the Yakima basalt and the Manastash formation fixes the age of the lava as early or middle Miocene. It is, in view of 
MIOCENE AND LATER. 17 

the age determination, possible for this formation that the name Yakima h[ts been 

applied to it. In earlier reports on central and southeastern 'Vashington, Professor 

Russell applied the namljs Columbia lava and Columbia River lava to thiR roek. He, 

however, included. not only the Miocene but also the Eocene and possibly the 

Pliocene basalts, as well as the hypersthene-andesite occurring along Naches River, 

which will be mentioned later as of . Pleistocene age. It became neeessary in 

course of detailed areal mapping to separate these various igneous rocks, and therefore the name Yakima has been applied to this formation, which includes only the 

basalt flows and interbedded pyroclastics which are of Miocene age and thus constitute 

a series that can be taken as a unit since it represents the products of a volc~nic 

activity uninterrupted by any other important geological process. The Yakima 

basalt is a normal feldspar basalt containing the usual constitue~ts, plagioclase, 

augite, and olivine. It is commonly a glassy lava, and in some localities large masses 

of pure basalt glass can be found. The rock is always dull in color and no crystals 

~an be distinguished except by means of the magnifying glass. In a few localities, 

notably Bald Mountain, in the· Ellensburg quadrangle, the series includes large 

quantities of fragmental material, the yellowish tuff's including irregular blocks of 

jet-black glass, some of whieh undoubtedly represent bombs ejeeted from the center 

of eruption. Along Yakima River the tuff bed3 and scoriaceoris lavas are less 

common tha~ the compact lava. . 

The number of lava flows in this series varies widely in different parts of the 

area. At no point is the whole series exposed. The sections shown in Yakima 

Canyon, where over 2,000 feet of basalt are exposed with neither the top nor base of 

the series visible, indicate that the actual thickness of the Yakima basalt iR probably 

to be measured in thousands of feet, and 5,000 feet is undoubtedly a conservative 

estimate. The columnar structure is the most noticeable feature of the basalt where 

it is exposed in the canyon walls. 

In a po~-tion of the Ellensburg quadrangle slightly later flows of basalt occur 

interbedded with the sandstone which overlies the Yakima basalt. These have been 

included in the W enas basalt, which is a formation of only local importance. 

Similar sheets of basalt are doubtless to be found in other portions of the great area 

covered with Miocene basalt. 

Ellensbu1'g fm'mation.-The only formation in central Washington which is 

known definitely to be of Miocene age is the Ellensburg sandstone. Collections of 

fossil.leaves made by Professor Rus~ell in 1892 near Ellensburg and by myself in 

1900 in Kelly Hollow have afforded material for the determination of the age of the 

formation, which Dr. F. H. Knowlton fixes as late Miocene. This determination 

correlates the Ellensburg formation with the Mascall formation of tM John Day' 

14493-No. 19-03--2 

.. 
" 

18 CONTRIBUTIONS TO GEOLOGY OI!' W .ASHINGTON. 

Basin in Oregon. The Ellensburg formation also resembles the Mascall in its composition. Both formations are composed largely of volcanic sediments, the sandstones and shales consisting of the finely comminuted andesitic material and the 

conglomerates containing pebbles and bowlders of andesitic lavas. In both cases the 

lav:t from which the sedimentary material was derive(l is not exposed within the area 

where the sedimentary roqks have been studied. This volcanie series doubtless 

occurs in the higher parts of the range to the west. 

Along Naches River over 1,500 feet of the Ellensburg formation are exposed, 

and the formation is characterized by coarseness of material, together with its 

prevailing andesitic composition, and also the commou occmrenee of stream bedding. A section of this formation exposed at White Bluffs, on Columbia River, 

is described by Professor Russell a as consisting of ''fine, thin-bedded sand and clay, 

with layers of pure white volcanic dust." The field t>videnee, therefore, indicates 

that in the Yakima region the Ellensburg formation is to be considered as of 

fluviatile origin, while farther east along the Columbitt the formation is plainly 

of truly lacustrine type. The cross stratification or stream bedding shows that the 

material was distributed by eastward-flowing streams. These stream sediments vary 

considerably in thickness within short distances, as would be_ expected. and at some 

points the stratification is so confused that individual heds can not be traced far. At 

localities, hoth in the Ellensburg and the Mount Stuart quadrangles,. bowlders of 

andesite measuring at least 5 feet in diameter. have been found in the Ellensburg 

conglomerate, proving that powerful currents must have transported the material. 

Later lavas.-The lava from which the Ellensburg sediments were derived was 

light-colored and contained homblende as an original constituent. Later lavas of 

a somewhat different type oceur in central Washington. The most prominent of 

these is the hypersthene-andesite which forms a long lava stream extending from 

the Tieton Basin west of the Ellensburg quadrangle down Tieton Canyon and 

along the Naches Valley m~arly to Yakima Riyer. This lava was erupted after the 

basalt and Ellensburg rocks had been uplifted to their present positions, and at a 

time when the topography was essentially the same that it is to-day. The lava 

is, therefore, of Pleistocene age, and where not exposed to erosion by Tieton River 

the lava stream preserves the form which it took when it came to rest. The surface 

of the andesite plateau between NachEls River and Cowiche Creek is exceedingly 

hummocky and full of undrained basins, while its margins, which have been affected 

by stream erosion, show the radiating columns into which the lava pttrted at the 

time of its consolidation .. 

Somewhat different lavas occur on the middle fork of Teanaway River, where 

t:hyolitic rock is seen to rest upon the eroded surface of the older rocks. The age of 

a Bull. U.S. Geol. Survey No. 108, p. D7. 
STRUCTURE. 19 

this lava is somewhat problematical, but evidently it is considerably younger than 

the Eocene rocks with which it is in contact. 

Pleistocene deposits.-ln the heart of the Cascade Range the valleys of the 

larger streams exhibit abundant evidence of glaciation. Within the area here 

_ described glacial deposits are not found except in the vicinity of Mount Stuart, 

which was a local center of glaciation. The valleys of Yakima River and most 

of its tributaries within the Mount Stuart quadrangle are gravel filled. These 

valley gravels attain great prominence in the upper valley of the Yakima and 

plainly once filled it to a considerable height, and diamond-drill records indicate 

that the river has not yet reached its former floor. The gravel terraces constitute 

a noticeable feature here, but are much less important than similar terraces upon 

the Columbia, which will be mentioned by Mr. Willis. In the Swank drainage 

basin these terrace gravels are auriferous and have been mined for many years. 

STRUCTURE. 

Certain of the structural features have been mentioned m the foregoing 

description of the formations. A more complete statement of what has been 

learned concerning the geologic structure of the region will be given here, since 

the area affords excellent opportunities for studying the course of events in the 

rlynamics of the mountain building. The two quadrangles present two types of 

,;tructure, but both are representative for the Cascade Range. 

1\fOUNT STUART QUADRANGLE. 

The oldest rocks were intricately folded and faulted before the intrusion of 

the peridotite, and this accounts for the greater. metamorphism which characterizes 

the schists, slates, and greenstones. The intrusive peridotite, now largely altered 

to serpentine, appears to have suffered similar dynamic action, but its record of 

deformation is doubtless much less significant. The rock is commonly crushed and 

sheared, but this condition indicates rather a lack of resistance on the part of the 

soft serpentine than intensity of the deformation forces. Tn fact, in large measure, 

the development of the zones of sheared material within the serpentine mass may 

have been due to the expansion incident upon the serpentinization of the peridotite. 

This alteration, with the resulting crushing, is known to be pre-Eocene in age, since 

the bowlders with slickensided sul'faces, so characteristic of the zones of shearing, 

are found in the basal conglomerates of the Swank formation. 

The jointing of the granodiorite is its only structural feature, since nowhere is 

the rock schistose. This batholithic intrusion doubtless played a considerable part 

in the pre-Eocene structure of the region, but no dcformation'of the older rocks can 

be definitely traced to this igneous rock, unless the hydrothermal alteration of the 

peridotite may be attributed to the intrusive granodiorite. The presence of small 
20 CONTRIBUTIONS TO GEOLOGY OF WASHINGTON. 

dikes extending from the latter rock into the adjacent serpentine shows the abi-ience 

of any later differential uplift of the massive granodiorite. 

The earlier Eocene rocks appear to have been subjected to deformation soon 

after their deposition. The folds arc open, with steep inclination of the strata 

exceptional. Within the area south of the Mount Stuart massif, a half dozen folds 

may be traced, the anticline::> and synclines having axes which trend northwestsoutheast. This structure, in part at least, antedates the eruption of the Tcanaway 

basalt, since that rock lies upon the somewhat eroded folds of the Swauk sandstone. 

Later, however, these folds may have been furthet· developed. 

The manner in which the rocks of the Swank formation nearly encircle the 

Mount Stuart· massif suggests that this forms the center of a great dome-shaped 

uplift, with the Tertiary formations dipping outward. The areal distribution favor::> 

this simple explanation of the structure, but detailed study of the various formations 

makes it plain that a careful distinction mnst be made between the different mo,·ements that have contribu£ed to the sum total of deformation. The attitude of the 

Mount Stuart massif at the commencement of the Eocene sedimentation can not be 

determined, except that this mass of granodiorite is known to have furnished the 

bulk of the detritus for the Swank sediments. These strata on the south side of 

Mount Stuart then became folded, as has just been described, and uplifted so as to 

suffer erosion. I£ the structure developed at this time may be determined by the 

distribution of the basaltic lavas which flowed out in the succeeding epoch, it appears 

that there was not only an elevation in the vicinity of Mount Stuart, but also on the 

eastern and the southern part of the Mount Stuart .quadrangle. The rise of the 

Wenatchee Mountains dome does not appear to have been so prominent a feature at 

this time as the development of an east-west trough in the central portion of the 

Mount Stuart quadrangle. In 'this depression, the molten lavas consolidated and the 

tuffs were laid down, and later the Roslyn sediments were deposited, the latter 

formation possibly covering in its original extent an even more limited area than 

did the Teana way basalt. 

Clealum Ridge, which bounds the Yakima Valley on the south, has certain 

topographic characters suggestive of a fault scarp. The structural relations show, 

however, that this marks the southern side.of the syneline developed in the Teanaway 

and Roslyn formations, and its topographte pronunence is due to the older rocks 

which nse here above the Eocene strata to the north. In middle Miocene tune this 

ndge ·bad mueh the same relatJ vc prominenee, as is shown by the way the Yakima 

basalt ahuts agamst and caps It, while filling the nmghbormg depressions. This 

post-Roslyn fokhng may have been coincident With the deformation of the Manastash 

strata, and thus belongs tc,> the close of the Eocene perwd. 
STRUCTURE. 21 

ELLENSBURG QUADRANGLE. 

The post-Miocene deformation can be ~:>tudied best m this quadrangle, where 

only .Miocene formations are present. Yet, while pre-Miocene structures can thus 

be avoided here, it is necessary to distinguish between the flexing or moderate ·folding to which the Yakima ·basalt and the. ~Jllensburg sediments were subjected soon 

after the deposition of the latter, from a later movement which affected the s~me 

rocks. These later structural features are so closely connected with the topographical 

features of the area that their discussion will be given under the heading "Physiography." . 

In the present connection, however, it may be well to call attention to a certain 

structural feature of the Yakima basalt. This is the almost universal occurrence of 

parting or jointing in the rock, by which the lava sheets are divided into the typical 

basaltic columns. This contraction parting took place normal to the surface of the 

lava flow, so that where the hasalt has its original position undisturbed the joints are 

vertical. The presence of innume1:able joints of this characte'r, of course, would 

greatly facilitate the flexing· of the basalt sheets; and, since the Yakima basalt is the 

more important formation in the Yakima region, this feature must not be disregarded 

in any consideration of the deformation of this area. Furthermore; this may serve 

to explain why the post-Miocene deformation, which will later be described as taking 

place at the surface, was not of the nature of faulting as that term is generally 

accepted. The structural ridges are not "tilted blocks" but anticlines. a 

HISTORY. 

The geology of central Washington may be best summarized by a brief resume 

of the geologic history of the area. 

The oldest rocks, probably of Paleozoic age, fur.nish a record of sedimentation 

and volcftnism, but this record has been greatly obscured by the altered condition of 

these rocks. This metamorphism in turn tells of the orogenic movements to which· 

the rocks have been subjected and of the action of intrusive magmas. 

The great intrusions of peridotite and granodiorite probably belong to the 

Mesozoic, and were events of the first importance in the history of this portion of 

the Cascade Range. The period of erosion subsequent to these intrusions was of 

sufficient length to allow these deep-seated bodies to be uncovered and deeply 

dissected. 

Froh1 these eroded older rocks was derived tlie material for the Eocene sediments, and the process of sedimentation appears to have been a rapid one within 

this area, smce several thousand feet o~ granitic sands and other sediments were 

deposited in early Eocene time, before uplift agriin inaugurated erosive activity. 

a This absence of faults in this area has been <liscussea in a recent paper by the autbor-Antlclinal mounta.in ndges m 

centrn.l WashingtoH' Jour. Gcol . Vol XI 1903 pp 166-177. 
22 . CONTRIBUTIONS TO GEOLOGY OF W .A.SHINGTON. 

Then began the first basaltic eruptions, the forerunners of the greater volcanism of 

the Miocene. This volcanic activity was succeeded by the quieter processes of 

sedimentation, by which the Roslyn sandstone was deposited in middle Eocene time. 

Somewhat later, in an aJ.jacent area, the deposition of the Manastash sediments took 

place, and the Eocene period closed with the uplift and folding of all of these 

Eocene formations. 

· Erosion continued well into the Miocene within this area, but ceased with the 

beginning of the great eruption of basalt, the many flows of which covered the 

greater part of central Washington like a molten sea. Immediately succeeding this 

epoch of volcanism came the deposition of .the Ellensburg formation, thick deposits 

of stream sands and gravels, brought down from a volcanic area to the west. 

Mountain-building movements followed this sedimentation of the later Miocene, 

and again erosion began to cut away what had been uplifted. The Pliocene and 

post-Pliocene history is recorded in the topography, and will therefore be discussed 

in the following chapter. 

Even this brief summary is sufficient to indicate how eventful has been the 

geologic history. Especially in Tertiary time is it true that this region has been 

one with relatively many changes. The many well-marked unconformities testify 

to the frequency of these geologic revolutions, so that geologic formations are 

easily separated upon the basis of structural breaks, whereas in other provinces 

such subdivision would need to be based wholly upon paleontologic evidence. 

PHYSIOGRAPHY. 

TOPOGRAPHIC D~SCRIPTIONS. 

MOUN'I' STUART REGION. 

Mount Stuart, 9,470 feet high, lies 15 miles east of the main crest of the Cascade Range, and forms the culminating peak of the Wenatchee Mountains. These 

mountains constitute a secondary range transverse to the general trend of the Cascades, but are char3cterized by the same rugged topogr~phy as the main. range. 

The mountain crests are deeply carved into spires and crags, while precipitous slopes 

descend into glacial amphitheaters where remnants of glaciers still persist. South of 

Mount Stuart, and extending almost to Yakima River, there is a belt of hardly less 

rugged topography. Here the valleys are deep and canyon-like and the divides 

are sharp and narrow. Dissection has apparently reached the extreme limit, and the 

topography may be termed mature. The gmdient of the streams is largely determined by rock hardness, and many of the minor topographic features, such as peaks 

and gaps in the crest lines of ridges, are also referable to varying resistance of the 

different rocks. Pl. III is a map of a portion of the Mount. Stuart quadrangle, 

showing the topography typical of this area. 
GEOLOGIC :MAP OFAPORTIONOFTHE ELLENSBURGQUADRANGLE,WASHINGTON 

Topography by A.E.Murlin Scale 

"==53=:lo'========i::===~z~===-=-==f3====4k======'5 miles Geology by George Otis Smith 

assisted by F. C.Calkins 

b.EG EN 0 

SURFICIAL ROCKS 

PLEISTOCENE 

SEDIMENTARY ROCKS 

NEOCENE 

Ellens 

-

burg formation 

(

Ellel~urg sandstone ihterb~Jation edded 

wichba.salt) 

IGNEOUS ROCKS 
TOPOG R.A.PHIC DESCRIPTIONS. 23 

The southern part of the Mount Stuart quadrangle includes an area quite distinct 

in its topographic features from that described above. Here there is a transition 

into the type of topography characteristics of the Yakima region. Whil; the streams 

may have canyons similar to those farther north, they are farther apart. The divides 

are broad and comparatively level topped. The valley of the Upper Yakima forms 

the dividing line between the two area~, and the surface geology is also quite different 

·on the two sides of this valley, in the vicinity of Clealum. · On the south the prominent escarpment of the Yakima basalt overlooks the river ~nd on the north are the 

lower ridges of Eocene sandstone. However, the differences in topography are not 

wholly due to the geology, as will be shown in a l~tter section of this paper. 

YAKIMA REGION • 

. That part of Yakima County· which lies adjacent to the course of the river of the 

same name possesses a topography that is unique. Its origin will be fully discu!'.sed in 

the following pages, so that only a brief description is necessary here. In its general 

:features this topography is very simple. Long canoe-shaped valleys, with intervening ridges, form a quite constant succession with the general trend transverse to the 

course of Yakima River. Some of the valley floors reach the river level while 

others lie several hundred feet above the bottom of the river canyon. The ridges 

rise from 1,000 to 3,000 feet above the valleys, with fairly gentle slopes and even 

crests, except where interrupted by the deep water gaps of the river. The relation 

of these ridges and valleys ~o the 1;iver may be seen in the sketch map of Yakima 

Canyon (Pl. VI); and the topography of a typical portion of the region is given with 

more detail in Pl. V. Pl. ,II shows very well the character of Yakima Canyon 

where it cuts through Manastash Ridge. 

This description of the topography would he incomplete without mention of 

the landslides that are common in central Washington, a topographic form fully 

described by Prof. I. C. Russ•eu in several papers. The active canyon cutting and 

favoring geologic structure has caused this area to afford wonderful examples of 

landslide topography. One of the best of these is on the southern slope of Cleman 

Mountain, and is well represented on the physiographic map (Pl. V). These landslides vary in size from some to be measured by cubic miles of displaced rock to others 

involving less than an acre of surface. In age this range is scarcely less striking, 

certain land~;lides antedating the high terrace gravels deposited when glaciers occupied 

the Upper Yakima Valley, while other slides are of so recent origin thatvegetation 

has not yet gained a foothold. 
24 CONTRIBUTIONS TO C-l-ROLOGY OF WASHINGTON. 

CASCADE LOWLAND. a 

IDRNTIFICATION. 

As was noted in the discussion of the literature, Professor Russell finds in the 

plateau-like surface of the Caseade Mountains evidence of previous recl!uction of the 

region "to a plain, or an approximately plain, condition nearly at sea level." This 

was tho "Cascade peneplain," the subsequent elevation of which resulted in the 

"Cascade plateau." In view, however, of the complete dissection of this plateau 

into a eomplex of sharp ridges and peaks, as described by Russell, it is evident that 

both plateau and peneplain are somewhat hypothetical. A general uniformity of 

altitude of the ridges and peaks of the central portion of the Cascades may be made 

out in certain districts, but so frequently are other peaks seen whicj:l rise above this 

'level that this class of evidence taken alone is far from conclusive. Indeed, this is 

best appreciated by those who have been most earnest in their se.arch for traees of 

the old peneplain. Furthermore, the date of the supposed planation has not hitherto 

been determined even approximately. 

The identification of possible remnants of the old lowland, if such a lowland 

existed, becomes most essential to the investigation of the later history of the Cascade region. By reason of the aridity of .its climate and consequent slight erosion 

the conditions in the area along the lower course of Yakima River are most 

favorable for the preservation of land forms. Erosive activity is mostly confined to 

the larger streams which head in areas to the north .and west where the precipitation 

is greater. Under such conditions it appeai·s quito- possible for deformation to 

outstrip e~·osion, with the result that the relation between structure and topography 

becomes at once both close and obvious. 

At first glance, the topography of this Yakima region is seen to be dependent 

upon structure. The ridges arc antidinal and the valleys synclinal. This relation 

necessarily involve~ a more or less perfect parallcl'ism between the surface anJ. 

the rock s.tructure. The parallelism may or may not be easily observed, but ·the 

determination of the degree of this conformity between structure and surface 

becomes of the greatest importance. 

The first hypothesis to suggest itself in the course of the field work in the 

northern part of the area here discussed was that the anticlinal and monoclinal ridges 

hounding the extensive Kittitas Valley were in a groat measure pre-Ellensburg. 

This valley· '\Vith its floor of Ellensburg sandstone, horizontal or only gently inch ned 

upward at the borders, has the general features of a structural basin in which lacustrine sediments have been deposited. Sue!]. a view would involve an unconformity · 

"Cascade is here used purely in a geographic sense. To express the period of development of this lowland, Mr .. 

Willis's term'· l\lethow" would.be more exact, and its use becomes necessary in his more detailed discussion of the "uecessive stages in the history of the Cascade Range. 
CASCADE T,OWLAND. 25 

between the Mwcene lava and the succeeding sediments, and the Ellensburg formation would be found to occur only in the synclinal basins where it had heen deposited. Further study of the area, however, ~bowed that the ch'Stnbution of the 

Ellensburg formation is too general to perm1t. of its being considered a local deposit 

of the character :;.uggested. 

The second explanatwn to lJe t.e::;ted in the field was that the soft Sttnd~tone, had 

been erpded from the crest::; and higher slopes of the anticlinal ridges, the Ellensburg thus being left only in the lower parts of the synclmal valleys. This apparently 

was the opinion held by Profer,sor Russell in his reconnau:;sance oL the Yakima 

region On this supposition, it was not pre-Ellensburg but post-Ellensburg movement that nphfted the anticlinal ridges of the area. Subsequent to the warping of 

the surface of the Miocene sediments, erosion removed the softer bed::; ftom the 

ndge'l, which determined the general distnbution of the Mwcene rocks as now 

observed, the upfolded basalt forming the ridges, and the Ellensburg bandstonc 

occmTing m the yalleys between. In this way there was a perfect conformity 

between surface and structure, although with a subsequ.ent destruction of tbm 

onginal surface, except in the floors of some of the basins or valleys, where the 

whole thickness of the sedimentary formation may have been preserved. The level 

tops of the ndges, therefore, while not preserving the original surface, would be 

parallel to It and m a way represent it, smce the sheets of re'listant basalt parallel to 

_the original surface have determined the present :mrface. 

This second hypothesis also had to be abandoned because field evidence did not 

support it. The essential feature of conformity between sur-face and strueture was 

found to be wanting, so that it became evident that the true explanation ir, less 

simple. ·where the even surface is best preserved, on the level crests of the ridges 

and on the long, gentle, and smooth ~lopes along the tlankt> of the same ridges, it is 

apparent that thi;; surface does not parallel the underlying 1ock structure. The d1p 

of the rock and the inclination of the slope agree in dnection hut differ in amount.' 

The rock dip commonly exceeds the slope, and higher heels occur in the valley than 

can be found on the r1dges, and while such valley:, may he un;:,ymmetrical with regard 

to the slopes on either side, the rock folds are even less symmetrical. 

Tracing the rock slopes of the valley sides upward until the even crests of the 

ridges are reached, lower sheets of the basalt are successively crossed, until it is 

evident that the crests of the antwlines have suffered eon~iderable erosion, bO that 

the h1ghest hed:, are found in the synchna1 valleys and the lowest on the cre~ts of tlie 

anticlimcal ridgef:>. The ref:>ult ha::; been more than the croswn of the softer :-.anclstone 

f:>trata from the ndge::; and their preservation in the ne1ghhonng valleys. The surface 

1~ thu~ an e10sion product and cuts aero~;, both the folded Yakima ba,alt and 

Ellen~burg sancl~tone. 
26 CONTRIBUTIONS TO GEOLOGY OF WASHINGTON. 

This beveling of rocks as widely different in their resistance to erosion as the 

hard, compact basalt which withstands the attacks of stream corrasion and the soft 

friable sandstone easily eroded even by the desert winds is especially noteworthy in 

connection with the present discussion. The absence of any scarp or other topographic form expressive of differential resistance of the two rocks indicates a. long 

continuance of the erosive activities producing this surface. Such perfection of 

planation could not be expected much short of reduction to a baselevel, so that the 

natural deduction from these observed facts is the former presence of an essentially 

level lowland over the area. Therefore, the third hypothesis was adopted in the 

field, namely, the ridges and valleys of the Yakima region represent a warped low land 

surface. The relation of this surface to the rock structure is not a simple one. The 

reduction of the area of previously folded rocks to a lowland caused any perfect 

conformity between the surface and the structure to be very exceptional, while on 

the other hand, the general or approximate parallelism between the two as ob::lerved 

at many points becomes explicable from the fact that the warping of the lowland 

surface was in the main along lines coincident with the axes of prelowland folding. 

This double deformation resulted in steeper dips for the ro~k strata, which were 

subjected to both movements, and more gentle inclination of surface slopes which 

have been affected only by the later warping. 

DEVI<JLOPMENT; 

The extent of this Cascade lowland .and the degree to which it was developed 

may next be considered. In the Yakima region exceptional conditions favor its 

preservation, !tnd the recognition of this physiographic feature is easy. Detailed 

mapping reveals the fact that the Cascade lowland was, in this area at least, a comparatively perfect one. Remnants of the ·old lowland now uplifted on the tlan)<.s of 

the anticlinal ridges are seen to have a remarkably uniform surface. On the ::iketch 

' map of a portion of the Ellensburg quadrangle (Pl. V) are indicated the portionH of 

the old lowland surface that have escaped destruction by later erosion. In the field 

the evidence appears much less fragmentary than on the map. The narrow gulches 

that ::lcore the sides of the ridges are unsuspected when one looks along the slope. 

What is seen is a gently inclined featureless surface extending from the even crest of 

the ridge to the valley floor below, often without a perceptible break. Thi!-:l ::iUl'face 

is commonly covered with baHaltic debris, uHually quite coarse, which has been 

·deriveu from the basalt exposed in the immediate vicinity. On ::lOme very gentle 

slopes a thick depo::iit of fine ::lilt is found. Whether or not this may represent 

a lowland deposit can not be definitely stated, but its present distribution is in part 

due to wind action. 

On this planation surface it is often impossible to trace the contact bet')'een the 
PHYSIOGRAPHIC SKETCH MAP OFAPORTION OF THE ELLENSBURG QUADRANGLE,WASHINGTON 

Topography by A.E.Murlin Scale 

>==<====-===o~========f=====i2========ai3'=====4~======="s miles 

Contour interval 100 feet 

Physiography by George Otis Smith 

LEGEND 

Remnants oflowland 

surface . 

Landslide areas 
• 

CASCADE LOWLAND. 27 

two formations. The accompanying illustration (fig. 1) shows such a case, and is 

drawn from a photograph of the spur east of Kelly Hollow on the southern slope of 

Umptanum Ridge. This may be considered the type locality for the recognition of 

the lowland surface. The plateau is several hundred yards in width and over a mile 

in length, and preserves its even surface to the very brink of the steep-sided gulches 

that bound it on the east and west. The surface is thickly strewn with angular 

bowlders of basalt, and there is not the slightest indication of the contact between 

the Yakima basalt and the overlying Ellensburg sandstone. On either side, however, 

on the walls of the gulches the position of this contact can be accurately fixed and 

its dip seen to be 20° . Here, then, the planation was complete and the resultant 

lowland surface is perfectly preserved. 

FIG. I.-Contact of Ellensburg sandstone and Yakima basalt-E, Ellensburg; B, Basalt. 

The profile of the deformed lowland, with the relation of this surface to the rock 

structure, i:s well shown in the section on Pl. VI. This section extends from Eilensburg to the vicinity of North Yakima, and while in a general way it is parallel to the 

accompanying map, it was made to follow as far as possible the unmodified spurs 

between the gulches that have been cut into the slopes. It represents, therefore, as 

well as a true section can, the lowland surface now warped to form the ridges and 

valleys of this area. 

On the slopes of Manastash Ridge, U mptanum Ridge, Cleman Mountain, Cowiche 

Mountain, Selah Ridge, and Atanum or Yakima Ridge remnants of the Cascade 

lowland can be detected. Farther north, in the Kittitas Valley, the old surface may 

be recognized on the slopes of Table Mountain and of Lookout Peak, where the 

inclination of the surface is seen to be less than the rock dip, in the sloping surface of 
28 CONTRIBUTIONS TO GEOLOGY OF W .ASHINGTON. 

the even-topped terrace of Ellensburg sandstone along Yakima River, and in the 

flat-topped mesa of similar material near the Normal School Building in Ellensburg. 

The identification of the old lO\vland surface becomes mon' difficult outside the 

area here described. Eastward, undoubtedly it can be traced to the plain of the 

Columbia, and to the northeast the even surface o:f Table Mountain appears to he 

continued in the even-crested but lower ridges just south of the mouth of Wenatchee 

Rivei'. Table Mountain thus. ~erves to connect physiog-mphically the Yakima 

region with the area described by Willis in ·the second part of this paper. 

North of I .. ookout Mountain, in the Mount Stuart quadrangle, as may have been 

inferred fron1 the description of the topography, there are no traces of a peneplain 

surface. In the western .portion of the Ellensburg quadrangle, where the ridges 

mentioned above unite to form a broad plateau, the distinction ean not be made with 

certainty between the old surface and a possible later erosionfeature, which may be 

determined by the gentle monoclinal structure of the basalt. Especially is this true 

on account of the absence of the .Ellensburg sandstone and the consequent lack of 

the best criterion for the recognition of the old lowland surface. 

The evidence of the reduction of a large area of folded Tertiary roeks to form 

, the Cascade. lowland appears conclusive. The date of the development of this lowland is fairly well determined, since folds involving late Miocene strata are truncated, while on the other hand the subsequent history of a large part of the region 

has been so eve~tful that the production of the lowland surface could not reasonably 

have been later than Pliocene. Previous to this Pliocene reduction, erosion does not 

appear to have ever produced anything like a peneplain in the northern Cascades, 

as far as its history has been determined. In view of the eventful character of the 

whole of the Tertiary, it is plain that the period of teduction to base-level can not 

be considered ~s including a11y large part of. Tertiary time, as bas been suggested by 

Russell. Uplifts or subsidences of the extent that are known to have occurred 

during Eocene and :Miocene time in this area must be considered as inaugurating 

new topographic cycles. Furthermore, the land surface that was flooded by the 

basalt flows at the beginning of the Miocene possessed considerable relief. This 

pre-Miocene topography has been preserved in a large measure from later erosion 

by the basalt, and where the capping is partially eroded away and stream canyons 

are cut down into the underlying formations the contact shows very conclusively. 

the character of the old surface. Such a locality is the valley of Taneum Creek, 

where it is at once seen that the prebasalt surface was such as to deserve to be 

termed rugged topography. It seems necessary, therefore, to restrict the period of 

the development of th!'J Cascade lowland to the Pliocene. a 

<tlt is of interest to note that in the John Day Basin, Merriam finds evidence of the erosion of the upturned ~lioccne 

formations eurly in Pliocene time: Bull. Dept. Geol. Univ. California, VoL II, No.9, p. 311. 
CONTRIBU'l'IONS TO G EO LOGY OF W ASHING'J'ON. 29 

CASCADE PLATEAU. 

CHARACTJ.m OF Till} UPLIFT. 

'Russell's term, "Ca::;cade plateau,'' is used in this paper as a convenient designation for the uplifted lowland surface. The term is of value as expressive of the 

change in attitude and as descriptive of the mass from which the Cascade Range has 

been carved. It is not, however, to be inferred that a broad, unmodified table-land 

once existed where now there are rugged peaks and deep canyons. The uplift. was 

not catastrophic but slow and gTadual, and further knowledg·e of its character may 

be gained :from the study of the Yakima region. 

Here, as has been noted in the previous Hection, the uplift was effected with 

·pronounced de:formation along well-defined axes, producing parallel ridges. This 

evidence in the region where the upraised surface has been so preserved that definite 

conclusions are possible suggests that the uplift of the Cascade Mountains was not 

necessarily of a b1;oad and general character, producing a dome with gentle slopes 

extending over thousands of square miles, but that the uplift was effected with 

similar local warping in other parts of the Cascades. 

This may serve to explain the lack o:f uni:formity in elevation of some of the 

higher peaks .. Such cases are cited by Russell," and he suggests four hypotheses to 

explain the greater prominence of the granite peaks, of which Mount Stuart is a 

type. The postpeneplain elevation of such masses is ·rejected on the ground that the 

structure antedates the period of reduction to base-level. Anothei· hypothesis is 

that these high peaks represent monadnocks on the old lowland, and another that 

the higher peaks, being composed of the more resistant granitic rocks, more nearly 

p1eserve the original general surface level of the Cascade plateau, which was about 

LO,OOO feet above sea level, while the peaks of softer rocks have suffered a general 

iliminution in height. A fourth hypothesis "calls for local upheavals since the 

Cascade peneplain was raised into a plateau and subsequent to the initiation of the 

present master drainage lines,"b an upward movement which is thought possibly to 

be still in progress. This last hypothesis appears to Russell to best explain the 

observed facts, and a modifi9ation of this may be here suggested in light of the later 

observations in the Yakima region. 

The uplift of the Cascade lowland to form the Cascade plateau on the present 

supposition was not a sinq~le, broad, fiat-topped, anticlinal uplift, but a deformation 

of more complex character. The Wenatchee uplift was not necessarily a local 

uplift subsequent to the main Cascade uplift, but rather a part of that uplift and 

eontemporaneons with the localized deformation in the Yakima region. The 

·wenatchee Mountains are thus comparable to Manashtash and U mptanum ridges 

to the so nth, and may, indeed, form the higher part of a somewhat broader uplift, 

a Twentieth Ann. Rept U.S. Geol. Survey, pt. 2, p!J. 139-142. b Ibid., p. 141. 
30 CONTRIBUTIONS TO GEOLOGY OF WASHINGTON. 

of which the Table Mountain-Lookout Peak ridge, 20 miles south of Mount 

Stuart, forms the lower flank. On the Wenatchee Mountains apparently no 

remnant of the old lowland surface remains, although such a surface is suggested 

by the level platform from which the upper 1,500 feet of Mount Stuart rises as 

a monadnock, hut on Lookout Peak and Table Mountain such a surface can be 

detected extending down into the Kittitas Valley, as noted above. It must be kept 

in mind, however, that such an uplift in no sense explains the rock structure, 

which greatly antedates this surface deformation, but, like the cases cited in the 

Yakima region, the later uplift was apparently along an older structural axis, and 

it is only hy detailed study of the basal contacts of the different Tertiary formations that the distinction can be made between Eocene deformation and the . 

deformation which followed the post-Miocene reduction to a lowland. 

VARYING DEGHEE OF DISSECTION. 

In the brief description of the topography of the Mount Stuart and Yakima. 

regions the difference in type was pointed out. The variation in degree of 

dissection is at once apparent., This is in no sense due to differences in the 

formations eroded, but has its origin in climatic conditions. On the eastern 

flank of the range the precipitation is scanty and erosive processes co~respon<:!.­

ingly weak. Only the larger streams that bead ·outside the arid belt accomplish 

much, so that deformation has been able to quite outstrip erosion, with the result 

that the warped lowland surface is preserved. On the higher s~opes, especially 

nearer the crest of the range, the precipitation is greater, and active erosion bas 

resulted in mature topography. 

It is on account of this deep dissection that there is little remaining to more 

· than sugge~:>t the Cascade plateau over large areas in the Cascade Mountains. 

Whether or not the acute peaks even approximate the old surface ean not be 

determined, but it seems probable that in the higher portions of the range there 

has been a general diminution of height. 

The cause for variation in degree of dissection other than that of a climatic 

nature is the length of the period during which erosion has been uninterrupted by 

crustal movement. In one area the topographic cyele may be continued from youth 

to old age, while in another region not far distant, in the same time, one cycle may 

be terminated and another inaugurated simply by a local uplift. The physiographic 

. stages enumerated by Willis in his paper have not been differentiated in the 

foregoing description of the central Washington area. It is doubted, moreover, if 

such distinctions can be made generally throughout this area, by reason of its 

physiographic development differing from that of the region described in the 

following paper. This difference appears possible, and indeed probable, since in the 
CASCADE PLATEAU. 31 

case of gaps cut by Yakima River in ridges only a few miles apart the record in 

one case is shown to be that of an uninterrupted uplift of the ridge, while the 

compound form of the other gap shows a halt in the uplift sufficient for widening 

the canyon in its earlier portion. 

A few points of connection between the two regions may be noted, however. 

The greater part of the Mount Stuart and Ellensburg quadrangles lies outside the 

limit of glaciation, and therefore direct reference of the date of topographic features 

to a glacial episode becomes difficult. The period of development of the Cascade 

lowland as described for the Yakima region of course corresponds to the Methow 

stage of Willis. The Entiat stage is poorly represented in the Mount Stuart 

quadrangle, and the only traces of topogmphy anted-ating the pre::;eht are found in 

the old valley of Cama·s Land and in several small areas now capped by rhyolitie lava, 

the pre-lava surface plainly possessing only moderate relief. Elsewhere in the 

northern half of this quadrangle dissection appears to have proceeded so far as to 

destroy au· evidences of an earlier stage, while in the Yakima region these later 

stages have not been separated, the uplifted Methmy topogr~phy having suffered 

extremely little modification. Smce the physiographic development is the result of 

the interplay of earth forces and atmospheric agencies, it is evident both must remain 

the same throughout a region to result in the same succession of physiographic 

stages. Climatic. differences appear to account for much of the topographic diversity, 

but the structui·al history is no less important .. It would seem futile, therefore, to 

expect uniformity in ~the physiographic record over wide areas in a province like the 

northern· Cascades if the writer is correct in his belief that the uplift of the range 

has bee·n complex rather than simple. However, it is no less evident that the more 

complete record that can be deciphered for the one area is of material value in the 

understanding of the other area. 

There is good reason to expect confirmation of the views here expressed in the 

course of futm;e work. Already the writ(;)r has detected remnants of the uplifted 

~owland surface in higher portions of the Cascades. The Cascade plateau was also · 

found to be exceptionally well represented immediately north of Mount Baker, near 

the international boundary .. Here there is not only a marked uniformity in the 

elevation of the ridges, but their crests a're broad and. even. Such topographic . 

characters belong to an older topography, and it is believed therefore that these 

features in reality mark the preservation of the lowland surface now uplifted to form 

the plateau with an altitude of over 5,000 feet. This plateau is incised by the deep 

canyons of Nooksak River and its tributaries, while upon it rests the volcanic cone of 

Baker. West of this region, toward the crest of the Cascades, the plateau character 

is lost and the more complete dissection makes the topography one characterize.d by 

the most acute peaks and TUgged mountain masses. In this higher porti01~ of the 
32 OON'fRIBUTIONS '1'0 GEOLOGY 01<' WASHINGTON. 

uplift the attack by erosive agencies has plainly been much more severe, and erosion 

has outbalanced deformation with the resulting destruction of the plateau type of 

surface. 

RIVEH HISTORY. 

In the higher parts of the Cascade Mountains it will probably be found that the 

only line of evidence bearing upon these physiographic problems is that furnished 

. by the streams. The antecedent character of such streams as the Icicle, which cuts 

across the granite mass of the Wenatchee Mountains, has been recognized by Russell, 

and furnishes additional proof of the existence of the Cascade lowland. In considering the history of such streams and their relations to the rock formation across which 

they have cut their canyons it is most important that a sharp distinction be made 

between the rock structure and the surface warping. The former is the result of 

succef:lsive epochs of dynarr.ic action preceding the Pliocene lowland reduction, while 

the latter comprises the elevation of the Cascade lowland to form the Cascade plateau 

or the uplift of the Cascade Mountains. 

In the Yakima region wlie~~e the lowland surface is best preserved the history of 

Yakima River, as it can be traced out, corroborates the physiography as stated in 

the earlier section of this paper. The antecedent character of this river is at once 

apparent, and, as noted in the review of the literature, Russell was the first to call 

attention to this important feature. As can be seen from examination of Pis. II and 

VI, the Yakima crosses the high ridges in a deep canyon in which the original 

meanders of the river are strikingly preserved. The course o£ the river antedates 

the uplift.of these ridges, and the warping of the lowland· surface must have been 

effected at a rate that permitted the Yakima to maintain its course without change. 

That there was no damming sufficient to cause the stream to seek a new channel 

is shown very conclusively in the vicinity of. ~orth Yakima. The river leaves the 

broad transverse valley in which that city is situated by cutting through Atanum 

Ridge at Union Gap, which is nearly a thousand ·feet deep. Five miles east this 

· ·ridge has a low saddle, purely structural in origin, which affords. an easy pass less 

than 200 feet above the valley floor. Here, had there been ar1y ponding of the 

Yakima waters during the uplift of the ridge, the river would surely have discovered 

the lowest point in the rim of the basini but there is no trace·of stream occupation 

of the ·pass. At other points where the Yakima cuts through other ridges the 

relations are hardly less convincing, since often the water gap inteiTupts the ridge 

in its highest part. 

The surface upon which this course of Yakima River was established plainly 

must have been the Cascade lowland. The independence which this course shows of 

the hard and soft rocks which made up that lowland points to the development of the 

meanders on a surface on which there had been a pei·fect reduction to base-level. 
U. S. GEOLOG ICAL SURVEY 

SELAH RIDGE 

UMPTANUM RIDGE 

SKETCH MAP OF THE YAKIMA CANYON} SHOWING POSITION OF ANTICLINAL AXES 

WITH PARALLEL GEOLOGIC SECTION, SHOWING ~LATION OF WARPED SURFACE TO STRlTCTURE 

.BY GEORGE OTIS SMITH 

ScaLe 

b==ooo=,;,;o...,.""""~b===l'2""""~~3b:==;;;4"""""""'~smi es 

Contour interval 200 'feet 

PRO FESSIONAL PAPER NO. 19 . PL. VI 

~--~--------------~a--NORTH 
CASCADE PLATEAU. 33 

Furthermore, the manner in which the lowland surface cuts across folds involving 

the Miocene sandstone indicates that the course of the Yakima was not determined, 

at. this time at least, by the slope of the uplifted lake bottom, as suggested by 

Russell. Here, again, the later warping must be distinguished from the earlier 

:folding of the rocks. 

Naches River, the most important tributary of the Yakima, is plainly also 

of antecedent character, since it has cut diagonally across one of the anticlinal 

ridges, uniting with the main river near the axis of the ridge (Pl. VI). The smaller 

tributaries of the Yakima in this region appear to be generally synclinal in position 

and also consequent upon the warping of the lowland. This statement, however, 

needs modification, since in the cases of 'V enas and Selah creeks portions of the 

streams cut across minor ridges. Selah Creek also flows along the north side of 

Selah Valley in a canyon the brink of which is above and over a mile distant from 

the axis or lowest part of the valley. Such a relation may be taken as showing that 

the course of the' stream is antecedent to only a portion of the warping of the 

lowland, the axis of that deformation having shifted' southward. W enas Creek is 

peculiar in that while it flows along the rather broad valley between Umptanum 

Ridge and Cleman Mountain and may be considered a synclinal stream, its sha,llow 

canyon is cut along the axis of a low anticline. This fold shows both in the rocks, 

the basalt appearing in the canyon, and in the deformation of the surface. The 

geologic and topographic relations of the vV enas Valley can be seen on the map of 

this area (Pl. IV). Back from the creek on .either side is a parallel valley across 

which the seasonal streams flow before joining the creek. The old lowland surface 

can be traced from the slope of the ridge across the back valley and up on the 

flat-topped hills overlooking the main creek, and the fact that basalt bowlders cover 

these hilltops where the underlying rock is sandstone shows that this is the lowland 

surface .. At one place the back valley has so level a floor that a stream coming 

down from the ridge sometimes divides on its alluvial fan and flows out to the creek 

through two separate canyons. The explanation of these relations that presented 

itself in the field was that vV enas Creek was at first a synclinal stream in the valley 

between the two ridges, but by a later uplift of the low ridge along the center of 

this. valley the creek cut down through the sandstone into the basalt beneath. 

There is evidence, too, that this later warping followed a structural line marked 

out at the time of the prelowland folding. The uplift of this medial ridge, a 

movement not exceeding 300 feet, was so gradual that not only did the main creek 

maintain its course but the tributaries suffered uo changes, but crossed the unaffected 

back valley and cut steep-sided gulches through the uplifted ridge. A simultaneous 

and indeed connected uplift also occurred a few miles up the valley, where the two 

14493-No. 19-03-3 
34 CONTRIBUTIONS 'I'O G EO LOGY 01!' WASHINGTON. 

northern branches of the W enas cut across an arch of basalt. The structure here 

can be seen perfectly in the canyons, and the flat crest of the ridge well expresses 

the lowland surfaces; and here again the absence of conformity between surface and 

structure is noticeable. This history of 'W enas Creek is simply an incident, of little 

importance except as it may show thttt the warping of the Cascade lowland was not 

a simple, uninterrupted movement, in some localities at least . 

. An interesting problem in connection with the history of the Cascade Range 

will be the identification of the system of antecedent drainage of which Columbia, 

Yakima, and W cnatehce rivers appear to be important parts. It will be at once 

noticed that these master streams are in no sense consequent upon the broad Cascade 

plateau with its north-south trend, as described by Russell, nor altogether upon such 

· minor uplifts as have been thus far recognized. These rivers are the streams that 

controlled and effected the reduction of the post-Miocene land surface to a peneplain, 

and the study of this drainage system may yield some data bearing upon the degree 

to which the planation was carried and upon the position of monadnocks and 

important divides. The extent to which it is justifiable to apply this hypothesis of 

the deformation of the old lowland surface into local domes or ridges, features 

measuring a few miles in shorter diameter, rather than into a broad plateau uplift 

measuring hundreds of miles in extent, can then be better discussed. 

PHYSIOGRAPHY OF THE SNOQUALMIE QUADRANGLE. 

Since writing the foregoing portion of this paper the author has extended the 

geologic mapping westward from the Mount Stuart area. The Snoqualmie quadrangle, which was surveyed in 1902, lies within the heart of the Cascade Range, and 

includes about 50 miles of the main divide between the Puget Sound drainage and the 

streams tributary to the Columbia. Such a region appears to furnish an opportunity 

for testing the wider application of th~ conclusions reached in the adjacent area. In 

the Ellensburg quadrangle erosion has been insufficient to destroy the traces of the 

Pliocene peneplain, now warped into the ridges described in the preceding pages. 

In the Snoqualmie quadrangle land sculpture has plainly reached a stage in which no 

traces of such a peneplain can be recognized. The topographic cycle is nearing 

maturity, and while the problem of interpreting the physiography is more difficult, 

it becomes interesting to make the test and to attempt to determine for this portion 

of the range the type of uplift which inaugurated the present cycle of erosive 

activity. 

' As a preliminary to this, it is helpful to review certain of the general principles 

of land sculpture as first and most clearly defined by Powell and Gilbert. These 

will be briefly stated in so far as they apply to the questwn in hand, which is, What 

was the character of uplift of this central portion of the Cascade Range~ Such 

general principles may be stated thus: 
CASCADE PLATEAU. 35 

Degradation is controlled by declivity, rock stl'ucture, and climate. As will 

be seen· below, the second and third factors may be omitted in the pr,esent consideration. While of great importance, they a.re essentially without value as criteria in 

this instance. Degradation, including erosion, sapping, and corrasiori, as well as 

transportation, increases with declivity. 

The work of ordinary degradation may be greatly augmented by glaciation, 

which, as will be· noted later, was not universal i~1 this area, hen~e glaciation has 

value for the purpose of this discussion. 

In the case of the simple uplift of a broad arch, there would result a flat top 

and steeper flanks. On the steeper flanks the greater declivity would determine 

the locus of the more effective degradation. With consequent streams, therefore, 

the maximum rate of degradation would obtain along the flanks of the arch, and at 

any stage there would result an axial ridge with axial peaks as the highest portion 

of the uplifted area. This result may be stated. differently, following Gilbert: There 

would be a persbtencc of divide, since at first it was the divide because an eminence, 

r.nd later an eminence because the divide. 

If the elevation was so slow in its first stages as to enable degradation to keep 

the axial region practically reduced, the resultant form would have a plateau 

character, as Powell has pointed out in' the case of the western portion of the Uinta 

uplift. There, however, the axial region is higher, although its prominence is 

inconsiderable when compared with the whole amount of degradation. 

With antecedent streams there is not the same persistence of divides, ·but rather 

a change due to the tendency of the streams to become more arid more consequenll. 

As developed by Campbell, the law of this migration of divides is that the divide 

tends to migrate toward an axis of uplift and away from one of subsidence. Thus 

it follows that in the case of a warped peneplain the antecedent drainage would tend 

to adjust itself to the warping and the streams would come to occupy the axes of 

relative de~res~ion with divides located tlpon the axes of elevation. In the case 

where the axis of depression shows changes in direction of pitch there would also 

be the tendency for the point on this axis, marked by divergence of pitch, to become 

also a divide. 

Now, turning to the Snoqualmie area, certain facts of observation may be stated, 

as they apply to the problem under discussion. · 

The main divide of the Cascade Range within this quadrangle is wholly upon 

:Miocene rocks, with the exception of 2 miles, where it is close to the contact of the 

Miocene with the Eocene. · The highest peak on this divide, which has an altitude of 

7,512 feet, and the lower ·portion of the divide for a considerable distance-with 

an altitude of 3,500 to 4,500 feet-are composed of Miocene volcanic rock with 

essentially the same physical charaeters. For this reason it appears evident that, 

as was stated above, rock character ts not at all a controlling factor. 
36 CON'l'RIBUTIONS TO GEOLOGY OF WASHINGTON. 

Climatic conditions are more or less uniform over this area, and any differences 

are dependent upon relative altitude, whiCh in turn is involved in the quegtlon of 

relative uplift which is being discussed. Climate must therefore be left out of the 

discussion, and it is plain also that it would not have any important bearing on the 

final decision. 

In the Lower Yakima region, where the river was antecedent, It was shown that 

the rate of uplift of the tranRverse ndges was not essentially more rapid than the 

rate of corrasion. The uplift, however, was greatly in excess of ordinary erosion, 

since many remnants of the uplifted surface remain. In the central region Yakm1a 

River carries its low-grade valley well back toward its head, so that the rate 

of uplift here has not been much greater than the maximum rate of corrasion No 

actual remnants of the old surface, however, are known in th1s mountainous region, 

so that while degradation has far from kept pace With uplift, it has been efficient 

enough to produce a topography that has many characteristics of maturity. The 

question of the antecedent or consequent character of the drainage again depends 

upon the mam question. 

As can be :,;een on the accompanying map of the Snoqualmie quadrangle (Pl. 

VII), in which only the 500-foot contours above 5,000 feet are shown, the trend of 

the higher portions of the area is slightly no;·th of west. The mam divide has a 

general trend of a few degrees east of north, so that the difference in trend is approximately flO degrees. Further, it will be seen that the high peaks on the divide are 

where it is crossed by these east-west heights. 

The stream-; 111 the viduity of the outlying heights are fully a& efficient as tho&e 

near the main divide, and in many ca&es possess the advantage of shorter courses and 

steeper gradient&. 

The thick mantle of soil which Is of common occurrence in the lower divide 

region mu&t be taken as strong evidenee of the ineffimency of transportation here as 

compared with the higher country. 

Glacial erosion has been an important factor in the northern area, characterized 

by a greater topographic prominence, while glaciation has been wanting m the lower 

parts of the main divide. 

As the third part of this section, the foregomg general principles and particular 

facts may be brought together and certain conclusions deduced. This process will 

com,titute the wider application of the hypothesi~ based upon the work in the 

Ellen:,burg quadrangle. The deductions are as follows: 

(a) Whatever the rate of uplift, the axial region shoul~ exhibit &ome topographic 

prominence. If uplift has outstnpped degradation, as i~; the case in this area, the 

axial ridge must be a distinctive feature 

In fact, the main d1v1de in the Bnoqualmie quadrangle fails to show any such 

prominence, except as was noted above. Therefore it is not the axml regwn. 
unite~~~!r~Pc[~~lsurvey MAP OF THE SNOQUALMIE QUADRANGLE;WASHINGTON CONTOURS OF 5000 FEET AND .ABOVE ,WITH 500-P.OOT INTERVAL, ARE GIVEN TO SHOW DISTRIBUTION 

OF HEIGHTS WITH REFERENCE •ro MAIN DIVIDE OF CASCADE RANGE 

Scale 

~~~o~~b:==~--4:==~4~Rmf===~~~7mWes 

\.c.d:.'""'=;...""?b:!'-.!k='l.....;7 kilometen 

.Dalllin ia mean 3ea level 
CASCADE PLATEAU. 37 

(b) Uniformity in pre~ent altitude of neighboring heights is suggP-stive of preexistent uniformity, everi. if not exactly indicative of the actual position of the older 

surface. A line connecting closely adjacent heights, even although these are sepa- . 

rated by canyons representing the work of efficient stream corrasion, is expressive of 

the position of an axis of uplift. 

In the Snoqualmie quadrangle the position of three such axes of uplift may 

be approximately determined. The southernmost of these extends· he yond the 

boundaries of this quadrangle, both east and west from the divide. Next, northward, 

is the high ridge between Naches and Yakima rivers, which is topographically 

and, in part at least, structurally the continuation of Manastash and Umptanum 

ridges to the southeast, which are known to represe~t upwarps of the old peneplain. 

Likewise, the third line of heights along the northern edge of the S~oqualmie 

quadrangle connects with the prominent Mount Stuart mass which constitutes the 

axial portion of the supposed VI/ enatchee upwarp of the lowland surface. These three 

lines of heights, which thus possess marked topographic prominence, are believed to 

indicate the position of three upwarps of the lowland surface. 

How nearly the present surface on these heights represents the old surface 

thus uplifted can not be so definitely stated. On the highest portions of the 

Naches-Yakima ridge the level tops are strongly suggestive of the old surface. The 

uniformity in the present altitudes is a striking feature _of the northwestern 

portion of the area, as illustrated by Mr. Willis on Pl. IX, and this uniformity may 

reasonably be considered the result of a gcnepl reduction of these. tops, which has 

been relatively slight in amount. 

(c) In whatever degree the system of divides fails to accord with the deformation; the drainage system shows similar lack of consequence. Streams cutting across 

lines of uplift must be antecedent, in part at least, and, with antecedent streams, the 

divides niay be in process of migration. 

In the Snoqualmie quadrangle the main divide has been shown to be not 

coincident with the axis of most marked surface deformation. Near the northern 

edge of the quadrangle the divide makes a sharp turn to the east and continues this 

northeastern trend for several mileR beyond the boundary of the area described here. 

This trend coincides more nearly with the axis of uplift indicated by the east-west 

line of heights. 

In the lower country of the Ellensburg quadrangle Yakima River is known to 

be antecedent to the warping of the peneplain and Naches River to be antecedent in 

a portion of its course and consequent in other portions. The history of the Puget 

Sound streams has not been studied. 

It appears evident, then, that these two ma:>ter streams may also have a mixed 

character in the Snoqualmie quadrangle. The Naches system is for the most part 
38 CONTRIBUTIONS TO GEOLOGY OJ!' WASHINGTON. 

consequent upon the two upwarps shown by the elevated ridges, and a: relatively 

high portion of the divide is at its bead where the downwarp between these two 

upwarps dies out. The most important tributary of the Yakima, Clealum River, 

appears to head somewhat north of the northern axis of upiift and is in that case 

antecedent. The Upper Yakima itself, however, plainly occupies an area of relative · 

depression and receives consequent streams from the slopes of the. upwarps to the 

north and south. There is some evidence, however, of partial inconsequence, but 

the position of the main divide which paralle18 for about 10 miles the upper course 

of Yakima River appears to be in part determined by the cross axi8 from which this 

downwarp pitches. 

A drainage system consequent upon complex warping of this character is thus 

less symmetrical than one consequent upon a broad ru;cb. The parHal inconsequence 

expresses simply the effect of the tmteceden.t character of these streams which was 

partially preserved wherever the rate of uplift or 'varping failed to be the determining factor. lngeneral, however, it is quite possible that much of the antecedent 

drainage may have been consequent upon prepeneplain structure, which was paralleled by . this later warping·, so that in the following· cycle the· antecedent streams 

ha~·e maintained their courses which may also appear to be consequent upon the 

warping. 

The degree of agreement of the drainage with the surface deformation may 

furnish data for the sepamtion of the uplift of the Qascade Range into distinct stages, 

as well as a more exact differentiatimt of the upwarps that eonstitute this uplift. 

(d) The ultimate deduction is that, whatever the relative proportion of antecedent 

and consequent character in the drainage system, the main divide for the greater 

portion of its length in this area neither coincides with nor parallels the axes of 

most marked deformation of the preexistent surface. The uplift to whieh the Casml(le 

Range owes its origin was not simple in type, but complex; and within this. area can 

be resolved into three well-defined upwarps, which, nioreover, are transv;erse to the 

main trend or major axis of the range considered over the larger area to the north. 

RESUl\fR. 

In the central W ashiiJgton area detailed mapping has given data for the 

recognition of a lowland surface, the fixing of the age of its development as Pliocene, 

the suggestion of the drainage system which controlled that reduction to a peneplain, 

and the determination of the kind of deformation to which this low land surface was 

later subjected. Such evidence has its bearing upon the broad problem of the origin 

of the great plain of the Columbia and the Cascade Range. To the east, deformation 

of the lowland has been less marked, while on the other side erosion bas largely 

destroyed the uplifted peneplain. Future investigation may be productive of 
RESUME. 39 

corroborative evidence over a larger area. The evidence in hand, however, is 

believed to be sufficient to prove the youth of the Cascade Range t~nd to suggest that 

the general type of 1ts uphft may have heen complex rather than simple. 

The data furnished by this study of the geology and physiogtaphy of central 

'Vashington may abo have a bearing upon broader prohlel)ls. The eventful character of Terttar} history in this province is noteworthy, as f:>howmg the rapidity with 

which geologic processes may accomplish their work. The Eocene sect1on measures 

not less than 10,000 feet in thickness and IS divis1ble mto four distinct formations, 

separable both hy physical hreaks and by differences in fossil floras. In the Neocene 

period not only was there the great volcanic act1vity and the later deposition of the 

Ellensburg sediments, but also widespread deformation and the production of an 

extensive peneplain were effected. 

Another feature of general interest i':l the deformation th1s peneplain has :mbsequently suffei·ecl. The evidence is helieved to be eonclusive that the old lowland 

surface has been warped so as to form antielinal mountain ndges and synclinal 

valleys. Ebewhere no such striking instance of peneplain modificatiOn has been 

described, and this unique character of the area is doubtlef:>s to be attnbuted m part 

to the structural characteristic::, of the jointed sheets of basalt involved in this deformation. Connected with this warpmg of the peneplam is the antecedent chatacter of 

Yakima Rtver, "hich f>erves as an exceptionally fine example of that type of stn·am 

in that it has mamtamed its course across not only one but several uplifted ridges. 

A thitd principle that demands recogmbon is the Importance of separating the 

results of two or more distinct periods of deformation. In this way onlT can there 

be any tt uc interpretation of structure in cases, such af:> the Yakima regwn, where 

the later movement largely followed the axes of earlier foldmg. Subsequent work 

in the Ca-,cade Range has strengthened the behef that such persistence of structural 

lines tlu ough successive epochs of defm mat! on IS not at all exceptional and must not 

be overlooked. 

The results of tlns physwgraphie study pronuse to greatly faCihtate future work 

in the northern Cascades, but they have also been pre::,ented here with the belief 

that they contnhute ':lomewhat to our understandmg of peneplains and their subsequent mod1ficat10n, wtth the resultmg difficulties attendmg then· recogmt10n and 

Identification. 

CONTRlBUrTONS TO THE GEOLOGY OF WASHINGTON 

PHYSIOGRAPHY AND DEFORMATION OF THE vVENATCHEE-CHEtAN 

DISTRICT, CASCADE RANGE 

llY 

BAILEY WILLIS 

41 

CONTENTS. 

Introduction .•.....••..• _ •..........•............................•. , ..............•....... 

Physiography .. ___ .. __ ..... _ .... : __ ..•....... _. _ ..... _ .•.....• _ ......................... . 

Descriptive analysis .... __ .... _._ ..• - __ ._ ..... _ ....•.... _._ .......... _ ... _ .... _. __ .. _ .. . 

Columbia Gorge, Wenatchee to Chelan _____ .... ------ __ .. _ .................. ~ .. _ .. . 

Columbia Canyon ... ---- ...... _ ......... _._ ... _ .... _._ .. _._ ......... _ .... ___ .. • 

Chelan Butte._ .... __ .... _ ... _ ...... __ ........ _ .. _ ... _. _ ... _ ....... _ .. , _ ..• __ . 

The eastern bank . _ .... ___ .... _ .. __ . _ .. , . _ .. _. __ .. ___ .. _ ........ _ ~ .. _ .. _ .. _. _. 

Badger Mountain and ·waterville plateau .. __ . _. _ ................................ _ .. 

Tributaries of the Columbia . _. __ .. __ ..... _ .. ___ .. _. _ .... __ . -·- ......... _: _. _ ... ___ _ 

\Venatchec Valley __ .... __ ....... _ ......... _ .. _ .... _ , ..................... _ .. . 

Entiat Valley . __ . _. ___ . _ ..... _ .. · ..... _, __ . __ .............. _., .......... __ .. _. 

Navarre Conlee and Knapp Coulee. ___ ......... _._ ............... _ ... __ ._. ___ .. 

Lake Chelan ... _ ....•........... _ ........ __ ....... _ ....... ___ . __ ._. ____ ...... _ 

Entiat lVIountains _ ... ___ . _ ... _. __ ....... __ ....... ___ ... _. _ . __ .... _ ...... _ .... __ . __ 

Chelan Mountains .. ___ ...... __ ._ ... : .. __ ...... _._ .... _ .. _ .. : .. _. ____ ... _ ... _ .. _•, .. . 

:Methow :Mountains._._ .. __ ....... __ ._ ..... _._ ..... __ ....... _ ... _ .... __ .... _ .. _._. 

Synthetic discussion _ ............ __ .... _. -.- _ ........ __ . _ ..... __ . _ ..... __ ......... _ ... . 

General statement ..... _ .. _ ...................................................... . 

lVIethow stage .. _. _ ..... _ ... _ ........ _ ............. _. _ ..... __ .... _ .. __ . _ .. _ .. __ .. . 

Conditions of development . : . ........... : ........... __ . _ .... _ ........ __ ... _ .. 

Criteria of recognition ........ _ .. _ ..... _ ....... ___ ._ ..... __ . __ ... __ ....... ___ .. 

Distribution and character of residuals ...... _ .. _ ..... _ .. _ .. _ .. __ . _ .. _. ____ . _ .. . 

Entiat stage ...... ~ __ ..... -......... -.- ..... _ ............................ _ ........ . 

Physiographic relations ... _ ............................ _ .. _ .. _ .. _. _ .. _ .. ____ .. 

Distribution and character of residuals ............... _ ........ _. _ ..... __ ...... . 

Degree of Entiat relief ....... __ ........... _ ... __ ........ __ ..... _. __ .. __ .... __ .. 

Glaciated aspects of Entiat heights:_ .... _ ... _ ........ _ ........ __ ...... ___ .. _ .. . 

.iHaturity of Entiat topography .................... _ .• _ .. _. _____ .... ___ ....... _. 

Entiat features in ariel areas ............................ _ ....... __ .... _ .. __ . _ .. 

Twisp stage ......... __ .........• _ .......... _ ............. · ...... _ ........ _ ....... . 

Characteristic features ...............................................•........• 

Development of topographic forms .................. _ ........ __ ........ _ ...... . 

Chelan stage ............ _ •.............. _ .. ~ .......•...................•...... _ .. 

Character of the record ............ _ ..... , ........................•...... _ .... . 

The basin of Lake Chelan .........................•...•.. _ ...•..•• __ ....•..... 

4:5 

I' age. 

47 

49 

49 

49 

49 

50 

50 

51 

53 

53 

·55 

56 

58 

64 

65 

66 

68 

68 

70 

70 

71 

72 

75 

75 

76 

77 

78 

78 

78 

.80 

so 

80 

81 

81 

81 
44 CONTENTS. 

Page. 

Deformation... . . . • . . . . • • • • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • . • . • . • . . . • • 83 

Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 

Fundamental propositions............................... . . . . . . . . . . . . . . . . . . 84 

Cascade uplift . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 

Height and extent........................................................ 85 

Limits of Cascade up warp .................................... ~............ 85 

J\'Iarginal flexures .... _.. . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 

.i\fethow downwarp ....... "............................................... 86 

JVIethow up warp .........•...................... ~. . . . . . . . . . . . . . . . . . . . . . . . . 88 

Chelan Butte upwarp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 

Waterville downwarp..................................................... 90 

Badger Mountain upwarp .................. ·................................ 90 

'Venatchee downwarp and upwarp......................................... 91 

Episodes of deformation ................................... :. . . . . . . . . . . . . . . . . . . . . . . . . . . 91 

Pre-Tertiary deformation ......... _.................................. . . . . . . . . . . . . . . 91 

Tertiary and post-Tertiary deformation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 

Causes of deformation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 

Direction of stress. . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . 92 

Dimensions of the Cascade block ............................... _. . . . . . . . . . . . . . . . . . . 95 

.Uplift by horizontal compression .............................•........... _ ... __ .___ 95 

.. 
ILLUSTRATIONS. 

Page 

PLATE VIII Map of \Venatchee-Chelan distriCt, Cascade Range_-._ ....... ______ .. ___ .-._--. 48 

IX Vww of the h1gh Cascades from head of Gold Creek, showmg the umform1ty of 

altitudes 50 

X 1

liew ot the h1gh Cascades from near Ca:,cade Pas~. showmg the muioruuty of 

al tJ tudes .. _ .. ____ . _ . ____ .. __ . ___ ... ____ .. __ .. _ .. _ ..................... __ -. 54 

XI V1ew ot Navarre Coulee ..... ___ .... _ ...... _ ........ _ ..... _ ......... _ ..... _... 56 

XII Chelan Butte from the north shore of Lake Chelan .... -........................ 60 

XIII The Narrows of Lake Chelan . __ ...... __ . _ ..... _ ............. __ .. _............ 62 

XIV Vww trom Chelan Butte, lookmg southwest down the Columbia Valley ...... __ . 64 

XV V1ew from Chelan Butte, lookmg northwest over lowet Lake Chelan to Stormy 

Moun tam nnd Navarre Peaks .......... _. _. _ ...... _ ............... _......... 66 

XVI Physiographic map ot the southern half of the Chelan qnafhangle .. __ ....... __ .. 72 

XVII Physwgraphlt: map of the northern half ot the Chelan quadrangle_ ....... __ ._... 74 

XVIII Physiographic map of the southern half of the Methow quadrangle .... _ .. _...... 76 

XIX Physiographw profiles m the Wenatchee-Chelan clistnet. __ ... _. ____ . _. _ .. ___ ... 78 

XX V1ews near Cascade Pass A, The f.Outhern slope of Boston l\lountam, showmg 

mclmed JOmt planes, B, The pmnacles south\\ e~t of the pass, Rho" mg vertJCal 

JOllltJng . _ . _ .. _ ... ______ .. __ . __ ... ____ .... __ . _ ..... _ . _ . __ . __ . . . ... ___ . _... £14 

FrG 2 D1agram of a block ............ __ . _ ..... _. _ . . . . . . . . . . . . .... _ ........... _ . : . ..... _. 96 

3 DmgrammatJc cross section oi a deformed mass ..... _ ... _ ............ _ ......... _..... 97 

45 

PHYSIOGRAPHY AND DEFORMATlON OF THE vVENATCHER-CHELAN 

DISTRICT, CASCADE RANGE. 

By BAIL]<]Y WILLIS. 

INTRODUCTION. 

The following article is based on observations made clueing several excursions in 

the Cascade .Mountains from 1895 to 1900, inclusive, and upon discussions with 

Messrs. I. C. Russell and George Otis Smith, to both of whom the writer is much 

indebted. When engaged in exploration in the same province, between 1881 and 

1884, the writer took little note of the physiographic aspects as such; to him they 

were then scenic aspects only, and impressive grandeur was the dominant idea they 

left. But upon returning in 1895, after eleven years spent in the Appalachians, the 

case was different. Association with Gilbert, Davis, Hayes, and Campbell in the 

discussion of physiog1:aphic relations of the eastern region prepared the observer to 

see the less evident, but not less definite, facts of the western province. 

In 1895 the writer traversed the western slope of the Cascade Range from 

Mount Rainier to Skagit River, visiting especially Snoqualmie Pass and Monte 

Cristo. At the former place the diversion of Snoqualmie River by a moraine dam is 

a conspicuous fact; The former eastern course leads by a wide valley to Lake 

. Keechelus, but· the diverted stream is now cutting a precipitous canyon in the 

western slope. The discovery of fossil leaves, classed as Miocene by. Knowlton, in 

graphitic slates in ~he crest of the pass suggested the post-Miocene uplift of the 

range. Near Monte Cristo wide general views were obtained, which swept the sky 

line from southeast by south and west to northwest, and i.t was apparent that many 

jagged pmtks rose approximately to uniform altitudes, which might reach or fall 

little short of an ancient plain. Stratigraphic studies of the Puget group of Eocene 

and :Miocene strata led the writer tentatively to assign this hypothetical plain to ;t 

late :Miocene date, and to place among the latest events of the Miocene epoch the 

uplift by which the old lowland was raised to a position at or above the summits of 

the Cascades. 

47 
48 CONTRIBUTIONS TO GEOLOGY OF WASHINGTON. 

To test the validity of these inferences, during succeeding years the heights and 

slopes of the range were viewed from many points, and the intersecting lines of 

sight, leaping· from peak to peak at nearly uniform altitudes, were thought to define 

clearly the general attitude of the ancient plain. Among the panoramic views upon 

which this hypothetical reconstruction of a vanit-lhed surface was based may be 

mentioned that from the eastern side of Mount Rainier, at 7,500 to 10,000 feet above 

sea, looking east and north; that from a spur' (6;000 feet) of Huckleberry Peak at the 

head of Gold Creek in the northeastern eorner of the Snoqualmie quadrangle, tracing 

the sky line throughout the entire circle exeept from northwest to north; that from 

Stormy Mountain (7,219 feet) in the Chelan Mountains in the western quarter of the 

Chelan quadrangle; and that from Boston Mountain (8,300 feet) north of Cascade 

Pass at the head of Stehe_kin Valley. 

In the meantime, in 189\-98, Russell reached the conclusions expressed in a 

preliminary paper on the geology of the Cascade Mountains in northern Washington a 

in the following terms: 

"After the time of long-continued erosion referred to above, when the Cascade 

region in northern Washington was reduced to a peneplain, there came a time of 

elevation, when the peneplain, or a very large portion of it, was bodily raised some 

7,500 feet at least, and thus became a plateau. In a broad·view of the region this 

Cascade plateau may be considered as of the nature of a broad, flat-topped anticline, 

or, as Dana would probably have called it, a geanticline. The rocks composing this 

uplifted region. had previously been folded, but we are justified in assuming, on 

what may be said to be general principles, that renewed movements occurred along 

these old structural lines. The main change was a general rise of a region of some 

10,000 or 15,000 square miles. The total area affected was much greater than this, 

as the Cascade plateau extends both north and south of the field under discussion. 

"One of the most remarkable features in the relief of the Cascade plateau is the 

seeming nearly level character of its original surface. The uprising was effected ' 

without pronouncf'd tilting. Perhaps, when our knowledge is more extended, it will 

be found that this conclusion is too hasty, but at prcsent,.from a study of the distribution of the rivers, as well as of the heights of the peaki.J left by erosion, it does not 

seem that the. plateau had a decided, if any, inclination toward either the east or 

the west. This is the most marked difference between the Cascade plateau in 

northern Washington and the Sie::-ra Nevada. The Sierra Nevada, as we now find it, 

is the result of the erosion of a tilted plateau, bordered on the east, from Owens 

Lake to Mono Lake at least, by a great belt of branching fractures and faults. No 

such belt of fractures and displacements parallel with either border of the Cascade 

plateau is known. The evidence is that the rise from each side of the plateau to its 

nearly flat summit portion is gradual." · 

Among the services rendered the writer by George Otis Smith was that of wellmaintained skeptieism in regard to recognition of an ancient plain over the Cascades. 

a Twentieth Ann. Rept. U.S. Geol. Survey, pt. 2, pp. 144-145. 
U. S . GEOLOGICAL SURVEY 

:.MAP OF' THE \1\'ENATCHEE-CHELAN DISTRICT 

CASCADE RANGE, W.1-\.SHINGTON 

Scale ~~-=~-==~-----_,;; ======~----...____.::-.-f>ntnes 

Contour interval 1000 feet 

LEGEND 

'R:rrme-r extent ofChelan.(Jlacler 

SlmUar gtaciets ~cupicd:Metltow 

ana We[\[ltcbee ·valleys.bnt their limits are rt.atdeterminea 

ra Contours on the warped surface of the Metl1 ow (Pliocene ) pcne ·· 

Jllainns rcst.ored ltypolhetically whel.'t" eroded 

PROFESSIONAL PAPER NO. 19 

Physiography by 

Bailey Willis ,Geo l ogist 
DESCRIPTIVE .ANALYSES. 49 

He asked for demonstration, which was difficult, since the suggestions of panoramic 

dews failed to convince, but duri"n~ his field work of 1900 he himself supplied the 

evidence of the existence of an old base-level plain on the hills of Yakima Valley, 

as stated in the first part of this paper. Of these results the writer was aware 

when he took the field in August, 1900, and he has found them of much value in 

tracing out physiographic relations in the vicinity of Lake Chelan. It would seem 

that the principal episodes in the history of the Cascade Mountains may now be 

stated with confidence. 

In the field work of 1900 the writer was fortunate also in having the company 

of Prof. R. D. Salisbury, and statements concerning the glacial phenomena were 

suggested chiefly and often wholly by his observations and interpretations; but he 

is not responsible for the form in which they may here appear. The profiles which 

illustrate this article are drawn from topographic maps of the Chelan and Methow 

quadrangles, surveyed by Messrs. Griswold and Farmer, topographers of the United 

States'Geological Survey. The writer has traversed much of the region with their 

maps in hand, and places confidence in the excellence and detailed precision of their 

work. 

PHYSIOGRAPHY. 

DESCRIPTIVE ANALYSES. 

COLUl\fBIA GORGE, WENATCHEE TO CHELAN. 

COLUMBIA CANYON. 

The broad flood of Columbia River emerges upon the valley about Wenatchee 

from a noble gateway in the Entiat Mountains. The elevation of ~he river is somewhat less than 700 feet above smt. On the east the slopes of Badger Mountain rise 

to 4,200 feet, from which altitude the long, e\'en profile of the summit declines gently 

eastward; on the west of the stream peaks of the Entiat Mountains in sight attain 

5,700 feet, and these arc the foothills of the Cascades. These heights of 3,500 to 

5,000 feet that thus hem in the river spring from a flood plain one-half to threequarters of a mile wide, and the profiles swing upward in convex curves, steepest 

near the foot. The effect combines grace and grandeur, the wide river, the broad 

gorge, and the great' mountains harmonizing in their proportions. 

Such is the view from a little distance. Upon entering the gorge the observer 

who follows the road along the western bank feels more closely shut in. On the 

one hand it is but a leap. into the dark-green river swirling past fallen blocks of 

gneiss; on the other the cliff is near, and its crest, 1,000 to 1,800 feet above, is impressively high. The boldest profiles occur from 4 to 7 miles above Wenatchee, and one 

conspicuous point-Ribbon Bluff-with precipitous face projects into the gorge 12 

miles farther upstream, 3 miles above the mouth of Entiat River. 

14493-No. 19-03--4 
50 CONTRIBUTJ;ONS TO GEOLOGY OF W .ASHINGTON. 

Cliffs arc not, however, the most characteristic features of the gorge. Along 

the eastern side they do not occur conspicuously, arid even on the bolder western side 

they give place frequently to steep slopes in which rocky ledges project sharply 

through scanty grass and sagebrush. These steeps terminate above in points of long 

spurs, which rise westward with gradual slope to the highest summits of the adjacent 

mountains. The prominent angle between the steeper and gentler elements o£ the 

profile is an important physiographic feature, upon which broad deductions are 

based. 

CHELAN BUTTE. 

Looking upstream from near Ribbon Bluff, the view includes a summit higher 

than its fellows on the west bank and peculiar in the long sweep of its spurs in a 

concave curve from the top to within 800 feet of the Columbia, where the slope breaks 

off into the gorge. This is Chelan Butte (3,892 feet), the eastern end of a ridge 

which lies between the Columbia and Lake Chelan. Its graceful profile presents the 

first view had from within the gorge of those higher topographic elements which lie 

between the mountain tops and the steeps that shut in the river .. The fact that this 

profile descends from Chelan Butte to within 800 feet of the river, whereas in the 

Entiat Mountains it ends 2,400 feet above the stream, is an index of the relative 

amount of recent uplift in the two place:g. 

The graceful silhouette of Chelan Butte is broken near the extreme summit by 

sharp, rocky ledges, which support a narrow but flattish crest. They are formed by 

granite dikes cutting the softer gneiss. Peaks of this partially cliff-girt form occur 

isolated but dominant among the mountains west of but near the Columbia, and will 

hereinafter be referred to as monadnocks upor; the Methow plain,a the remnants of 

which, so far as recognized in this region, will be described later. 

'l'HE· BASTBRN BANK. 

The eastern side of the gorge differs markedly from the western. Not only is 

it in general not so bold of profile, but the forms of the slopes are genetically distinct. 

:For a few miles above Wenatchee the bluffs on the east of the river almost equal 

those on the west in height and boldness where they rise to Badger Mountain; farther 

upstream, however, the slope recedes gently from the river, and, growing steeper, 

ends 2,000 to 2,300 feet above the stream in a mural escarpment 150 to 300 feet high. 

This wall crowning the height is the edge of a sheet of basaltic lava whose darkbrown color and columnar structure give it emphatic value in the otherwise gray 

· and tawny landscape. In general the summit is even and nearly level, it being the 

western margin of the plateau of eastern Washington, and the line of the escarpment 

a Cascade plnteau, the term used by Russell to designate the surface which might be restored over the Cascade Range, 

would be used as the name of the peneplain, but its prior use (1872) to denote a stratigrnphic series renders it unavailable. 

Methow peneplain is therefore here applied, from. an important spur of the Methow .1\Iountnins, in which the old level is 

well exhibited. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO, 19 PL. IX 

VIEW OF HIGH CASCADES FROM HEAD OF GOLD CREEK, SHOWING UNIFORMITY OF ALTITUDES. 
BADGER MOUNTAIN AND WATERVILLE PLA'rEAU. 51 

is in sympathy with other level lines that cross the slope at various altitudes. Some 

of these lines arc terraces due to landslides, others in ravines are terrace-like embankments that may be traced to the work of glaciers, and others much more continuous 

and nearer the river are stream terraces of the great Columbia itself. These last are 

represented on the western side of the gorge also. · 

Among the features which in any complete account of. the· region should 

be fully described are the several types of terraces of this eastern side of the 

gorge-the landslides, most common where the heavy columnar mass of basalt weighs 

upon the underlying schist and granite; the ice-built terraces, which are in part 

effects of tiny glaciers that gathered in the shaded lee of the plateau, in part results 

of occupation of Columbia Canyon by a tongue of a large glacier which, descending from the north, flowed down the river to a mile below Chelan Ferry; and the 

river terraces that extend for miles along the stream, their even tops sloping down 

its course and their perfect embankments rising near Chelan Ferry as much as 600 

feet above the water. But all these features belong to a chapter of the history 

which is herein touched only incidentally-the very recent episode of glaciation. 

BADGER J\IOUNTAIN AND WATERVILLE PLATEAU. 

In its great sweep westward, southward, and southeastward across Washington 

Columbia River marks out the central plateau of the State. Most elevated. near 

its western margin, this highland slopes in a general way east and southeast, and it is 

diversified both by channels and by uplands. The former, such as Grand and Moses 

coulees, appear to have been canyons of a large stream, probably the Columbia, but 

they are now nearly dry. The uplands are elevated portions of the plateau, connected 

with the lower parts hy continuous slopes, usually not d1stinguished by scarp or 

steep . 

.Badger Mountain and the V..7 atcrvi.lle plateau arc parts of this central district, 

situated at its extreme western uiargin and separated from the easte: n foothills of 

the Cascade Range only by the canyon of the Columbia. It will appear later that 

there is in fact no separation in the sense that the mountain district west of the river 

has had an orogenic history different from that of the plateau east of it. But the 

rock structures and conditions of sculpture are so unlike that the two provinces 

appear at first sight to be physiographically and geologically distinct. 

In the vicinity of Waterville the plateau presents an undulating surface, with a 

maximum but very local relief of 200 feet in a tenth of a mile. Well-defined but 

shallow drainage channel;;; converge southeastward from a flat divide at 2,900 to 3,000 

feet above sea.· They constitute the headwaters of Moses Creek, wh].ch soon falls 

into a newly cut ravine. There was no water in any of the head streams in August, 

1900, and the flow is not only intermittent but never large. The surface is deeply 
52 CONTRIBUTIONS TO GEOLOGY OF WASHINGTON. 

mantled with fine soil, derived from decay of the underlying basalt. Active corrasion would qqickly gully and remove it. The surface forms arc rounded and filled 

out by blown material, showing that wind rather than water is now the efficient 

modeling agent; yet the landscape as a whole presents relief due to stream work. 

In the fiat spaces about the margin' of the plateau, in the even divide between 

Coberly and Moses creeks, and in table hills southeast of ~Taterville, there are areas 

of considerable extent which ·are not now being eroded by streams. They present 

fin,ttish surfaces, due to earlier low-level erosion,. and are herein correlated as 

remnants of the plain once cut upon the basalt surface. From these remnants this 

plain is traced into the Cascade or Methow plain recognized by Russell. 

Badger Mountain appears as a long, low hill when seen from the north from 

Waterville plateau. Although it rises 1,400 feet above the plateau, its slopes are so 

gentle, its surface so smooth, its length so extended, that it doe::> not appear to be 

more than a hill. The summit is broad and flat, and long spurs with even slope 

extend not only northward but also southward several miles into the high valley of 

Rock Island Creek. Only when seen from the depths of the Columbia gorge or in 

relatioi' thereto is Badger Mountain impressive, as toward the canyon it generally 

presents one or more mural esearpmcnts of basalt crowning a confusion of landslide 

terraees, and it is conspieuous in height and mass. 

The details of relief cut in its northern and southern slopes are more marked 

than those of the Waterville plateau, as might be expeeted from their steeper grade; 

but they are not aecented by rocky walls, as are the similar features of Moses and 

Coberly creeks. Careful study of the two slopes of the mountain in riding across it 

discovered no conspicuous rock outcrops on the north or south. In the district 

of basalt flows, in which Badger Mountain m~s, outcrops are rare where tl1-e dip 

of the basalt sheets and the surface slope nearly or quite agree; the outcrops are, on 

the eontrary, conspicuous and continuous, like terrace walls, where a gentle dip of the 

sheets is beveled by a steeper sm·faee slope. It is inferred, therefore, that the basalt 

sheet,; conform in a genm·al way to the arched surface of the mountain, as they do to 

the surface of the Waterville plateau and of the synclinal valley of Rock Island Creek. 

When the physiographic features of the mountain are compared with those of 

the plateau they are fonnd to be very similar if not identical. In the plateau there 

may be recognized fiats of an old lowland and later slightly developed relic£. On 

Badger :Mountain tl;w flats may be identified in surfaces of long unmodified spurs 

and in the level summit, while the later relief appears more deeided)y developed, 

but of the same stage as that of the plateau. The mountain therefot·c appears to be 

a part of the plateau, raised to a greater elevation without interruption of the slope. 

In consequence of altitude and accented grade, the mass is undergoing more rapid 

corra>;ion than the adjacent plains of like rock, but the process of dissection has made 
TRIBUTARIES OF THE COLU:MBlA. 53 

ver3~ little progress. Hence we may infer comparative inefficiency of the process or 

recency of relative uplift, or both. 

TRIBUTARIES OF THE COLUJ\IBIA. 

The traveler following the eastern bank of the Colqmbia erosses but a single 

stream, Cobei"ly Creek, whereas along the western bank from vVenatchee to. Chelan 

he eneounters in 35 miles six streams, of whieh three are rivers. This distinction is: 

not limited to the short stretch under consideration, it being true of the Columbia. 

throughout central 'Vashington. From SpoKane River to Snake River, 275 miles, 

no tributary of notieeable size enters from the east, while seven large rivers come in 

from the west. On the one side is an arid plateau; on the other, well-watered 

mountain systems. 

Wenatchee River, Lake Chelan, the independent streams between them, and 

their tributaries drain approximately. 30,000 square miles of high, mountainous 

country, which receives for the most part very heavy precipitation. The volume of 

·water which they contribute to the Cotumbia is accordingly large. The three, 

domin~nt rivers are Wenatchee, Entiat, and Chelan. Their courses are practically 

parallel, and at first sight, as stated by Russell,a appear to be simply consequent 

upon the surface slope of the uplifted Cascade Plain. Evidence will be given later 

to show that Chelan is a composite stream, ma<:te up of several parts united by 

piracy; and it is probable that Entiat also consists of parts of what were f~rmerly 

distinct streams. The history of Wenatchee Rivm· is not made out in detail, but it 

has a wider branching system than the others, and may, like them, be a composite 

river. Reason will be shown later, however, for considering it an older river than 

Chelan, and one which has lost to the Chelan system an important part of its headwaters. TheY akima and Methow systems appear to be equivalent to the Wenatchee 

in age and general history, and these three may be classed with the Columbia as 

repreoenting a drainage system from which the existing one is derived by adjustments. 

The seveml valleys which join the Columbia from the west between Wenatchee 

and Chelan may now be appropriately considered. 

WENATCHEE VALLEY. 

'vVenatchee Valley is developed on a mass of arkose sandstone lying between 

harder granite and gneiss. ·whatever the antecedent conditions of drainage, adjustment to this soft mass and opening of a wide valley must result in time. The deg-..ce 

of adjustment attained and the extent of the valley appear to be such as to show that 

there has been adequate time. In one respect, however, the river exhibits an eecentric course. After flowing some miles southward in the sandstone area, it turns 

abruptly westward and crosses into the adjacent granite on the west. Russell 0 

a Twentieth Ann. Rept. U. S. Geol. Snn·ey, pt. 2, p. 146. b Ibid., pp. 140 and 158. 
54 CONTRIBUTIONS TO GEOLOGY OF WASHINGTON. 

describes the depth of the canyon which the river has cut in granite as 3,000 feet, and 

the length 6 miles. An interesting problem is thus pt·esented, and several alternative 

hypotheses occur iu explanation. . First, there is the idea that the meandering river 

was superimposed upon sandstone and granite at a time when their surfaces came to 

a common peneplain.a In this view the eccentricity is an original feature which 

adjustment has not yet modified. Second, the broad valley which exists in the 

sandstone may be looked upon as the original course of Wenatchee River, and the 

eccentricity of the present channel may be ascribed to diversion. A possible cause of 

diversion may be found in glaciation. As described by Russell, theW cnatchee glacier 

once filled the upper valley as far down as a point abreast of the present entrance of 

the river into the granite canyon. Under appropriate topographic conditions the 

ice might be competent to carry a stream flowing on its western margin over a divide 

into a small ravine adjacent, and thus the conditions for development of the present 

relations might be established. The fact that Upper Wenatchee River flows along 

the western side of its broad valley lends color to the hypothesis. 

At present a low divide crosses the sandstone area south of the elbow which 

carries the Wenatchee into the granite. The divide is so low that it does not 

interrupt the view up the valley from Leavenworth, and its sky line falls in with 

the general elevation of neighboring hills of sandstone, while all such hilltops lie 

much below the grmiite and gneiss mountains on either hand. It is this view of a 

continuo1,1s valley which suggests the hypothesis of a formerly straight and now 

diverted course of 'Venatchee River. The divide, nevertheless, requires explanation. 

Its elevation above that part of the valley upstream from it is a condition which 

could have resulted only from degradation of the upper valley, since the ''Venatchce 

ceased to flow straight south aet·oss the divide. The depression of the upper valley 

may have occurred (a) through post-Gbcial work of the diverted riYer; (b) during 

a glacial epoch through ice erosion by the '"7 enatchee glacier; (c) in interglacial time 

by degradation due to the diverted river, provided the stream was turned into the 

granite area during an cai·lier glacial epoch than that which is well known by its 

evident and widespread phenomena. Two epochs of glaciation arc recorded in 

separate tills {the Admiralty and Vashon tills) in the Puget Sound Basin/' and the 

glaciers were there confluent from the Cascade.s, yet in the area of glacial erosion 

records of one epoch only haye been found. Jt, is possible that general uplift and 

erosion were incidents of an interglacial time and that the earlier glacial sculpture 

and deposits have been largely obliterated. Detailed study of the profiles and 

gravels of vV cnatchee Valley and Canyon may throw light on the problem of two 

glacial epochs. 

a Twentieth Ann. Rept, U.S. GeoL Survey, pt. 2, p. 140. · 

b Willis, Bailey, Drift phenomena of Puget Sound: Bull. Geol. Soc. America, vol. IX, pp. 111-162. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 19 PL. X 

VIEW OF HIGH CASCADES FROM NEAR CASCADE PASS, SHOWING UNIFORMITY OF ALTiTUDES. 
TRIBUTARIES OF THE COJ,TJMBIA. 55 

The effects of deformation which are de:;,crihed m the last sections of this paper 

may also he considered in this connection, and the area about Wenatchee Lake may 

be found to have heen depre~sed or warped down relativel~r to the lower valley. 

Entiat RIVm· i<:. a r-;mall stream among its fellows. It lie& hetween ''T euatchee 

and Chelan rin:n·s, and its drainage basin is surrounded by the basins of these 

stream&, which join around it~ head and cut it off from the higl1 glacier-bearing 

district of the Cascades. The ~tream is about 35 miles long and hao. a straight 

course (S. 28° K) to within 3t miletl of its mouth, whc1e it turns eao.t to the 

Columbia. The valley is very symmetrieal and is limited by the para11el Entiat 

and Chelan mountain:;,. 

The Entiat flow.;; in a deep gorge, comparable in form with, hut narrower than, 

that of the Columbia. Near Its mouth the :;,teep slopes are about 1,500 feet lngh, 

and on the south, up to 2,600 feet above the liver, the tributary ravines are sharply 

chiseled. North of the stream and 1,\)00 feet above it begin gentler slopes and broader 

features, which are connected with tho:;,e that lie above the inner gorge of the 

Columbia. Up the Entiat, about the junction with Mud Creek, the canyon appears 

to be but 1,200 feet deep and near Stormy Creek not mme than 1,000 feet. These 

differences are coordinate with the grade of the Entiat, which from Stormy Creek 

to the Columb1a falls 950 feet, and thn:;, smks that much deeper below the practically 

leYcl contour of the ba:,;e of the outer gentle topographic form&. 

Three miles above Stormy Creek the Entiat Valley bot.tom is half a m1le wide 

and the slopes of the canyon arc continuously steep for 3,500 feet up to the closely 

adjacent sumnnts of Tyee Mountam and the Chelan Mountmn~>. Th1s phase of the 

gorge is related in aspect and position to the section of Lake Chelan above Twentyfive Mile Creek. Each present<> the appearance of a youthful canyon modified by 

glaciation, and their development will he further di&cu:-;s:;,d in &tating the history of 

Lake Chelan. ' 

The position of the Entiat Valley does not appear to be due to any zone of rocks 

weaker than others :;,o far as the d1stnhntion of rock mas!'es 1s known hy examination 

of float 111 the river near its mouth and by traversing the Chelan Mountains. The 

area Is one of gncis~>es and intrusives, probably relatPd in intricate manner. The 

rocks of ·the cre:;,t of the Chelan Range are, indeed, dikes which are relatively hard, 

and the divide if, determined by them; the Entiat Range may be l'.lmiharly crested; 

but these d1kes of hard materials are not confined to the summit:;, They presumably 

occur irregularly within the Entiat Basin. 

A simply fortmtous conditwn might determine the position of a minor valley 

like that of the Entiat between two larger ones. but there are some reasons for 
56 CONTRIBUTION~ 'L'O GEOLOGY OF W ASHING1'0N. 

believing that chan<'e hu,s not been u dominant factor in thi:-; case. It will be shown 

that the Entiat Mountains are located on an uplift, which was there more pronounet>d 

than along adjacent lines. The trend of thts uplift Is northwest-southea~:>t, and It now 

limits the Ent1at drainage hasin on the southwest. The Chelan :Mountains are probably along a .similar line of uplift. Thus the Entiat Ba~:>in apparently oecupwH the 

position of a depression between two uplift::;, possibly a downwarp vall{'y. 

The stream is, however, older than the most recent earth movements which have 

affeeted its present course. The uplift of the regwn in general, and of the BadgerEntiat Range in particular, occurred in two di::;tinct epi:o.ode.s, and the tint limited 

the Entiat Valley. The nver appear;:, then to have flowed ;:,traight to the Columbia. 

Its old channel is marked by the gap in the spur southwest of its present month, 

the gap which is ~>hown on the topographic map at the contour of 2,600 feet, and 

which is t,lOO feet below the hilltop that rises northeast of it. The interpretation 

is that the stream was checked by the later movement on the Radger-Entiat axis, 

and was diverted to a new course, its pre:-;ent ea&terly one. It has :-;mce then cut its 

inner canyon down 2,000 feet below the old one. 

NAY ARRE COULEE AXD KNAPP COULEE 

Navarre and Knupp coulees are unlike ordinary valleys m ,..,everal respects. 

First, they carry no running water, except that from a ~;pring which in each tlows 

out near the level of the Columbia, at the foot of a gravel terrace. Second, the 

rivulet:, that now flow from beneath the gravel filling and which gather from gulches 

tributary to the main coulee at·e diRproportionately smaH when compared to the 

valleys they occupy. Third, the canyon:-; which constitute their present upper 

sections continue beyond the divide and e:xtend into the Chelan Rat-lin. Fourth, they 

have wide, fiat floors of gravel, the one 400, the other 600 feet above the Columbm. 

This gravel filling appears as a conspicuous terrace when viewed from the eastern 

bank of the Columbia. Ji1fth, the wash from the adjacent hills is ~;o copiow;, that 

alluvial cones are bmlt clear across the fiat-bottomed coulee, and thus sections of It 

are converted into hollows, which occasionly hold water and accumulate sediment. 

In cross section the two coulees are miniatures of the Columbia gorge. Each 

exhibits a narrow valley or canyon within a wider valley and thus record:, ep1:,odes 

of development which are directly related to those of the great river. Like the 

Columbia, Navarre stream and Knapp stream had their beginnings back in the time 

of the ancient plain whose remnants barely survive in neighboring he1ghts. 

Navarre was always much larger than Knapp, and its features a~·e more conspiCuously developed. 

From the Columbia the ascent to Navarre Coulee if:> by a sharp V guleh, beyond 

which one rides out upon the surface of the gravelly fiat 400 feet above the river 
U. S. GEOLOGICAL SURVEY PROFESSION AL PAPER NO. 19 PL. XI 

VIEW IN NAVARRE COUL EE. 
TRIBUTARIES OF THE COLUMBIA. 57 

(see Pl. XI), and for 5 ~niles may follow the level bottom. One then enters a 

narrower canyon; marked on the west side by a conspicuous vertical wall of granite 

800 feet high, and in three-fourths of a mile passes through this gate into a pretty 

glade lying level between wooded slopes. The head of this glade is an amphitheater, 

little more than 200 yards in diameter and steeply hemmed in. It is silent now save 

for the sighing of the pines, but at its farthest point is the vacant site of a cascade, 

whose voice once resounded from the surrounding hills. The fall was about 150 

feet and the volume of water was large. The stream was a river flowing· from the 

Chelan glacier, and by this pass the great mass of gravel which fills the. lower canyon 

entered Navarre Coulee. At the end of the latest glacial episode the ice sank within 

. the Chelan Basin and the river found a lower eastern course. The cascade, however, 

is only the latest incident in the history of the valley. Before the ice time Navarre 

stream had cut the inner canyon and before that the outer valley. 

Above the cascade's vacant channel, aR one rides out upon a gravel terrace from 

which the slope descends 600 feet to Lake Chelan, the emphasis of the environment 

is upon the recent glacial condition; but reverting to the earlier history one finds no 

apparent source of the older stream. The valley is cut clear through the divide and 

ends in the air high above any streams which might once have been its headwaters. 

Knapp Conlee closely resembles Navarre, but on a smaller and less emphatic 

scale. Near its south~rn end and western side bare rocks rise boldly in the face of 

the gravel terrace below the channel of the latest glacial stream and formed the sill 

over which the cascade dashed. Northward and 500 to 600 feet above the Columbia 

the surface of the gravel terrace extends 2 miles to a _narrower section, which corresponds to the conspicuous canyon of Navarre, and by this pass the open slope above 

Lake Chelan is reached. Again the valley is cut through the divide and at least 400 

feet below it, but the headwaters of the stream which accomplished the task have 

been so diverted to lower channels that they can no longer flow through the pass; 

indeed, they can no longer be positively identified, except that they must now be 

tributary to Lake Chelan. 

The history of these coulees is thus seen to comprise in order (1) an early stage 

of valley development at a surface now above the 2,000-foot contour; (2) a phase of 

canyon cutting, which was sharply accentuated in a space just south of the Chelan 

Basin; (3) the diversion of the headwaters; (4) the reoccupation of the channels by 

glacial streams, which, being heavily overloaded, _filled them with gravel; (5) their 

present condition, in which they are being aggraded by wash from the steep side 

slopes, and reexcavation has begun in gullies facing the Columbia. 

These ineidents of individual history, especially the accented canyons and diversion of headwaters, fit in with other evidences in the interpretation of the character 

and distribution of deformation of the region. 
58 . CONTRIBUTIONS TO GEOLOGY OF W ASHlNGTON. 

LAKE CHELAN. 

Lake Chelan is a slender body of water 65 miles long, whose southeastern end 

lies open to the sky between the grass-grown hills of the outer Columbia V all~y, 

while its northwestern lies in shadow between precipitous mountains in the heart of · 

the Cascade Range. There are sandy shallows near its outlet, but beneath the cliffs 

of its upper course the water is profoundly deep. 

In brief technical phrase, the lake basin is a canyon modified, deepened, and 

dammed by glaciation. The canyon ,is that of the Stehekin-Chelan River, which rises 

in latitude 48° 30' in glaciers of the Cascade Range itt altitudes of 5,000 to 8,000 feet. 

The headwaters descend very abruptly, 1,000 to 1,800 feet in the first mile below the 

glaciers, and combine in a U-shaped valley of gentler grade, the fall being 2,500 feet 

in 23 miles. This section is cut in rock bottom. For 12 miles farther downstream 

the valley is floored with bowlders, coarse gravel, and sand, and the slope is but 20 

feet to the mile, ending in the delta which the stream is building into Lake Chelan. 

The gravel-filled section of the valley is no doubt deeply cut in the solid rock, 

since but a short distance beyond the front of the delta the lake is more than 500 feet 

deep. For a distance of 35 miles the depth varies from 1,000 to 1,400 feet, 1,419 

being the maximum as yet sounded. As the water surface is but 1,079 feet aboye 

sea, the bottom of the lake is for a short stretch 300 feet below sea level, and an interesting question is raised as to how so deep a basin originated. Fifteen miles from 

its outlet the lake begins to shallow, and in its lower reach does not exceed 200 feet 

in depth. 

The water is retained at i~s· present level by a dam of sand and gravel, which in 

the section exposed by Chelan River is seen to consist of several suf)cessive members, 

i. e., soil, coarse stream gravel, till, very coarse gravel in pockets or channels, and 

cross stratified sands. The base of the drift is not exposed. This drift dam fills the 

preglacial valley by· which the Stehekin-Chelan River once reached the Oolum bia, 

and the present outlet turns from the drift into the gneiss and granite south of it, 

and has there cut a deep rock gorge. 

The topographic environment of Lake Chelan presents several distinct phases. 

(See Pis. I and XIII.) About the eastern end the general aspect is that of a wide, 

open valley bounded by hills 1,500 to 2,500 feet high. The slopes are marked by 

long, low spurs, whose profiles rise moderately, but with increasing angle upward 

to the summits. Slight hollows between them have consistent grades. The surface 

is that of rmi.ture topography characterized by profiles which are concave upward, 

but on traversing the hilltops one notes in their flattish and rounded forms that the 

stage of maturity is not everywhere completely developed, else the ridge . crests 

would be sharp, and sympathetic with the active corrasion of the slopes. The earlier 

phase is not, however, distinctly traceable in these summits. 
TRIBUTARIES OF THE COLUMBIA. 59 

Upon this mature surface are cut and built certain younger features. ·where the 

major spurs sweep downward to the level that once was the valley floor and become 

gentle in slope, they end abruptly in steep or precipitous facets which break directly 

down to the lake shore and are about 400 feet high. These bluffs might readily be 

attributed to ice erosion, in view of the conspicuous evidences of glaciation in the 

Chelan Basin·, hut they are traced and correlated with the steeps which wall the inner 

gorge of the Columbia below the limit of any glacier, and they therefore are similar. 

elements of the Stehekin-Chelan canyon which was cut within the mature. topography of an. earlier date. 

Terraces which fill the hollows and occasionally skirt the slopes for some 

distance occur at various -levels up to 1,100 feet above the lake. Their topographic 

position, relations among themselves, and constitution show that they formed in 

lakelets confined on the hillside by spurs and on the now open side by the glacier 

which occupied the Chelan Basin. A full disc1,1s;;ion of them belongs to the glacial 

history of the region. 

In the view from Chelan Butte northwestward, the lower section of Lake 

Chelan is seen for a distance of about 15 miles to occupy the wide basin just 

described. Its trend in this stretch is north by west 8 miles, and thence due north 

7 miles. Along the western side of the latter reach runs a bold ridg·e, whose even 

crest is 3,600 to 4,200 feet above the lake and whose eastern face des~ends precipitously nearly to the water. A marked featur~ of its ;;carp is a deeply stained 

surface, freshly exposed, which is locally known as Red Slide. The lake trends 

wes~ward around the northern end of Red Slide ridge and disappears from view 

among lofty mountains. The Methow Range lies north, the Chelan· Range south, 

both rising to more than 7,000 feet above sea within 5 or 6 miles of the lake, and 

both sending out long, high spurs which maintain altitudes of 6,000 feet above sea to 

within 2 miles or less of the lake. From these spurs descend very steep slopes, 

scored by little ravines and worn by glacial action. 

Sunk deep among the mountain ~eights, the fiord-like lake extends 32 miles. 

The grandeur of the scenery readily lends itself to superlative description, but exact 

statement must be moderate. The walls of the canyon are sloping, not precipitous. 

Bare and gray and desolate, the mountain sides and cloud-draped peaks are very 

impressiv~, but though their height be 6,000 feet above the lake they nowhere tower 

in precipices like Yosemite walls. The maximum inclination is usually near the 

water surface, and for a hundred feet or so may locally approach 60 'degrees. Generally it is less than 40 degrees. And from this steepest facet the profiles rise in a 

curve which is convex upward, and pass into the nearly level spurs of the adjacent 

ranges. The narrowest and boldest section of the canyon is just above Safety 
\ 

\ 

60 CONTRIBUTIONS ~1.'0 GEOLOGY OF WASHINGTON. 

Harhor Creek. It lS called the Narrows and is shown in the view Pl. XIII, and in 

profile in fig. 5 of Pl. XIX. 

The physiographic features of the fiord lake are readily eon·elated with those of 

the Columhia River gorge. The steeps of the latter are not only homologous with 

the walls of the :former, but they are mutually traceable one into the other through 

Navarre Coulee, Knapp Coulee, and the Lower Chelan Basin. That they are due to 

a eommon activity-the familiar corrading action o:f a stream-is apparent. ThejT 

differ, however, in certain aspects. The gorge of the Columbia exhihits acute pinnacled rock ledges cropping through 8lope~ of soil and loose rock. The canyon 

of Lake Chelan presents massive rounded bosses of rock, cleaned and worn down by. 

a mighty scouring action. This is the work of ice which, aR a glacier, flowed 

through the fiord, driven by the accumulations in the tributary valleys of the Cascade 

Range. 

The diver:-;e aspects of the Chelan Basin invite discuss ton. Its lower valley sectwn 

and its upper fiord-like extent are of different topographic stage:,, the one bt>ing 

mature, the other young. Their divmsity may be explained as the result of eithrr 

one of two conditions or of their combination. The lake basin below Twentyfive 

Mile Creek may be cut in softer rocks than the part above that stream, and its more 

advanced topographic development may be due only to a consequently greater rate 

of erosion. Or the section below Twentyfive Mile may actually date farther ba<'k 

in time than the upper portion, and may have attained itR present btage through 

longer exposure only. But in the view now held by the writer both of the;;e mnditions have been effective. 

As to the rocks in large masses they may be considered in two clas~Sei:l. The softer 

ones are gneiss and schist; the harder are jointed intrusive rocks. Gramte occurring 

as dikes outcrops in bold ledges in Chelan Butte and elsewhere, and is one occasion 

of the high divide south of eastern Chelan Basin. Rhyolite-porphyry and graniteporphyry dike.;; stand out ruggedly as the c1 est of the Chelan Range, and :;imllar 

rocks occur extensively in the Methow Range, at least about the head of Safety 

Harbor Creek. On the other hand, the rocks :;een north of the eastern part of Lake 

Chelan are micaceous and schistose. In ISO far as these differences coincide with 

heights and hollows, we may attribute a certain effect to them, and the most conspicuous mstance of such coincidence is found about Lake t;helan below Twentyfivc 

Mile. Bnt on the whole the region is characterized by mdifl:erence of topographic 

phase to rock structure, and the distinetions descrihed are not adequate in themselveR 

to explain the great features of Lake Chelan. 

A number of facts go to -;how that the Stehekin-Chelan canyon 1s a composite 

one, and that the development began at the ea:;t and extended westward. In that 

• case the eastern section dates farther bacK., and 1ts advanced topographic aspectR 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 19 PL. XII 

CHELAN BUTTE FROM NORTH SHORE OF LAKE CHELAN. 
TRIBUTARIES OF THE COLUMBIA. 61. 

may thus be explained as not only more aged in appearance, but actually older. lf 

the valleys of Navarre and Knapp have been properly interpreted as beheaded, 

Chelan Canyon, below Twentyfive Mile, carries their headwaters. The drainage 

once consisted of Chelan Brook, a little stream which entered the Columbia at the 

old outlet of the Chelan Basin half a mile above its present mouth, and which headed 

east of Knapp Coulee; of Knapp Creek which drained certain slopes north of the 

present Lake Chelan; and of Navarre stream, which was composed of First Creek, 

Twentyfive Mile, and the brooks that enter Lake Chelan east of Falls Creek. It is 

doubtful whether Falls Creek then existed, and a divide is thought to have extended 

from Navarre peaks of the Methow Mountains uninterruptedly across to the Chelan 

Range. According to hypothesis, little Chelan beheaded Knapp, greater Chelan 

captured upper Navarre, and the valley below Twentyfivc Mile was established in its 

present course. 

This piracy is attributable in part to adjustments of drainage to hard and soft 

rocks. As already stated, both Navarre and Knapp coulees exhibit sharply accented 

canyons near their northern ends. These are in hard granite. Columbia River, if 

it encountered this same granite axis farther east, would reduce the obstacle much 

more rapidly than the smaller streams could, and thus little Chelan Brook, flowing 

on softer gneiss with a low outlet might gain s11fficient advantage to divert its 

stronger neighbors. · It is believed that this condition existed and was infl11ential in 

effecting the readjustment, but its sufficiency is doubted unless it was aided by other 

circumstances. 

Deformation is believed to have played an important if not a major part in the 

diversion of upper Navarre and Knapp to Chelan. As will appear in the synthetic 

study of the Methow plain, its remnants are recognized south of the ridge which 

connects Baldy Mountain and Chelan Butte and on the western part, but not on its 

eastern extensiuu. (See Pl. XVII.) The area of the ridge appears to have suffered 

greater degradation, which is attributed to that greater elevation of which there is 

evidenee in the position of the Methow plain. This upwarp stretched across the 

courses of Navarre and Knapp streams and ponding their upper eourses, made them 

an easier prey to little Chelan. The accented canyons which they now exhibit as the 

upper sections of the coulees are interpreted as evidence of the efforts n).ade by the 

streams to maintain themselves before capture. 

The preceding interpretation suffices only for the Lower Chelan region. The 

extension of Chelan drainage above Twentyfive Mile and to the Stehekin is still to 

be explained, and that explanation depend:,; chiefly upon the :,;lope, which connected 

the upraised surface of the Methow plain at an altitude of 8,500 feet or more with 

the level ·of that same topographic surface east of the Columbia at 3,500 feet. This 

slope i:-; shown in fig. 4, Pl. XIX, east of Navarre Peaks, but it is there probably 
62 CONTRIBUTIONS TO GEOLOGY OF WASHINGTON. 

gentler than it was toward the basin of lower Lake Chelan at the place where Chelan 

drainage headed against it. There can be no question hut that the development 

of that slope caused vigorous growth' of the head branches of streams rising on it, 

and that capture and diversioi1 of any river less favorably situated must result. 

That there was such a river appears to follow from the recognition of an old valley 

whieh now lies at a great elevation and is completely dissected. In describing this 

feature it will be convenient to name it, and it will be called Russell River." 

The valley of Russell River wns first recognized in the summer of 1899 in a 

view east and northeast across the Entiat and Chelan mountains. On the southeast 

the Mount Stuart group formed the right wing, and on the northwest the high 

summits of the qascades were the left wing. In the far distance on the horizon 

lay the basalt plateau of central Washington. According to expectation, the Chelan 

a.nd Entiat .mountains, extending from the high Cascades on the west to the basalt 

plateau, should descend in a general slope without marked depression along the 

mid-sections, or decided elevation in the eastern ends. But such depression and 

elevations were striking features of the view. Stormy (7,219 feet), Baldy (6,432 

feet), Tyee (6,688 feet), and heights in the eastern Entiat mountains not yet mapped 

stand higher th~n those portions of the ranges between them and the Cascades. 

The profiles of the lower mid-sections of the ranges are peculiarly flat and suggested 

cross section':l of a shallow valley. The heights east of the mid-sections are traversed 

by the deep canyons of Eritia~ River and Chelan, such canyons ~ts should be formed 

by streams attacking an elevated bench and retrogressively cutting into it. The 

slope .of the supposed l>ench forms the .eastern. side of the Cascade mass and is a 

necessary feature connecting the mountain block with the lower surfaces on the east .. 

And a streftm flowing on the bench and parallel to its face in the general position of 

a valley corresponding with the lower mid-sections of the range would be peculiarly 

liable to capture. 

·when in 1899 this hypothesis of the former existence and complete diversion of 

Hussell River was framed, equal consideration was given to another explanation. It 

was that the depression along the mid-sections of the ranges was due to a zone of 

weak rocks, which had wasted faster and yielded lower divides between the attacking 

streams. In 1900 these hypotheses were tested so far as practicable. The depression was clearly recognized from various points of view on the Chelan and Methow 

mountaim;, and it was visited at the only place accessible to the route followed. 

This place is in the southwest corner of the Methow quadrangle (see Pl. XVII), about 

the head of Lake Creek. The divide between Lake Creek and Lake Chelan is 5,900 

to 6,000 feet above sea, and the heights on the e.ast rise above 6, 700 with points over 

7,000, while those on the west reach 8,500 feet at a considerable distance. The low 

a In honor of Prof. L c. Russell, who first published an account of the Methow plain, on which the river flowed 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 19 PL. XIII 

NA RROWS OF LAKE C HELAN. 
TRIBUTARIES OF THE COLUMBIA. 63 

pass is a mile and three-quarters wide between the points of the 6,000-foot contour. 

The ridge was examined for the presence of a weak zone of rocks,· but it was found 

to consist of gneiss cut by granite i.u essentially the same relations and of the same 

general character as the masses of the heights on either side. Specially active work 

of the streams opposed to each other across the divide is not evident, the crest being 

broad and deeply covered with soil. The further thought that the depression was 

due to locally energetic agencies of present streams or possibly of past glaciers, was 

therefore not sustained. 

On the other hand, positive evidence of Russell River, such as river 'gravel, w~s 

not found, and indeed could hardly be expected to have survived. The ancient 

stream thus remains in a measure hypothetical rather than known, but its supposed 

course may be sketched as follows: The headwaters of Russell River are now known 

as the Stehekin and are diverted to the Chelan system, the diversion having occurred 

at a point now about 10 miles southwest of Navarre Peaks (Pis. VIII and XVIII), 

and. 6,100 to 6,300 feet above sea; that is in the air 5,000 feet or inore above Lake 

Chelan. Thence the course of Russell River was across the divide at the head of 

Lake Creek, the valley floor lying probably above the lowest sections of the ridge as 

it is now sculptured. Lake Creek may be a surviving remnant of the old stream, 

representing a beheaded section which was· cut off also from its lower course by 

the :B~ntiat. Between Entiat and vV enatchee rivers the valley of Russell River is 

marked in the heights, and the course was probably southwesterly. Finally Russell 

River joined the Wenatchee, of which it was the northern and possibly the principal 

branch. 

Reverting now to the development of the Chelan system, we have to consider 

what may have been the conditions if Russell River did not exist. In this case the 

writer has little to present that is satisfactory: It may be assumed that Chelan and 

Stehekin constitute a con~equent stream, whieh has flowed in its present course 

without any such complex adjustments as have been discussed; but in that ease the 

beheaded condition of Navan·e and Knapp coulees remains an unsolved and apparently insolvable problem. If again it be suggested that Navarre stream formerly 

included not only Twentyfive Mile but also all the upper Chelan-Stehekin drainage, 

the valley of Navarre is disproportionately small, and the diversion of so large a 

river to the present outlet appears altogether improbable. 

The youthful aspect of Chelan Canyon above Twentyfive Mile remains a fact, 

whatever the early history of the drainage system, and is due to and evidence of 

recent uplift of the mass in which it is sculptured. Its significance in 1;elation to 

deformation will be further considered in discussing that subject. 
64 CONTRIBUTIONS TO GEOLOGY OF WASHINGTON. 

ENTIAT. MOUNTAINS. 

To see the Entiat Mountains against the sky and in their relation to the Columbia 

gorge and Badger Mountain, one should ascend the spur between Navarre and 

Knapp coulees to an altitude of 3,100 feet. Thence Badger Mountain presents an 

unbroken even-topped height which is taken up by the Entiat Mountains and carried 

westward for 2 miles till it rises into conical peaks 800 feet higher. (See profile 7, 

Pl. XIX.) The otherwise uniform sweep is broken by the great valley of the 

Qolumbia, which clearly exhibits its inner gorge and outer slopes. Restoring what 

the river has cut away, the topographic continuity of Badger and Entiat is apparent, 

and they are also geologically a unit, since the basalt and gneisses occur in similar 

relations in both. 

The continuity of structure and profile of the mountains which the Columbia 

divides shows that they are of one mass that moved as a unit in the uplift of the 

region. Similar reasoning and conclusion apply to 'iVaterville plateau and the mesa 

north of Entiat River. They also, though divided, are of one n1ass, but their surfaces lie 1,000 to 2,000 feet lower than the mountains. Tho river's trench is deeply 

cut in both masses, but if we filled it to the brink between the plateau and the mesa, 

the stream could not flow across the higher mountains before it. It is clear that 

when the river adopted its course the mountains were not higher than the plateau, but 

that since that time the Badger-Entiat mass has been raised higher than the region 

north of it. As has already been pointed out, this uplift sufficed to cause the diversion of the lower part of Entiat River, but it did not rise with sufficient rapidity to 

turn the great master stream, the Columbia. 

The broad flat at the eastern end of the Entiat Range, 4,500 to 4,900 feet above 

sea, corresponds in extent with a basalt remnant. The dip of the basalt is not less 

than 3 degrees and probably nearer 5 degrees to the north. The slope of the surface 

is about H degrees in the same direction. The dip and slope therefore appear to 

diverge 150 feet or more to the mile. If we assume that at any time the surface 

was level, the basalt then dipped 1t or more degrees, and the level crossed the basalt 

beds at a slight angle. It is more probable that the surface declined slightly down 

the course of the Columbia and was ent across the nearly level basalt. Both have 

been tilted in the uplift of the Entiat Range. 

Though small, the angle at whieh the flat surface and the basalt bedding diverge is 

important, since the surface is thereby identified as one of erosion in contradistinction to one of structure. The evidence is slight and by itself insufficient to establish 

a conclusion, but it is sustained by the fact that in this· region similar flats are cnt 

across structurally indifferent gneiss a~1d granite, and it is corroborated in the 

Yakima district by the definite observation~:> of G. 0. Smith, with which it is in line. 
PROFESSIONAL PAPER NO. 19 PL. XIV 

VIEW FROM CHELAN BUTTE, LOOKING SOUTHWEST DOWN THE COLUMBIA VALLEY. 
DESCRIPTIVE .AN.ALYSIS. 65 

CHJ<,LAN MOUNTAINS. 

From Columbia River at Navarre Coulee an Indian trail leads to Stormy 

Mountain, the highest point of the Chelan Rang·e, and following the crest for some· 

miles in a northwesterly direction crosses the Entiat Valley and the Wenatchee 

Mountains toward Leavenworth. Like most Indian routes h1 this region, it was 

chosen from among the many possible ones because it presented little difficulty to 

the passage of horses, the ridges followed being of gentle rise. To this fact of 

topographic form and to exceptions to it, attention is now called. . 

Aftet· a sharp scramble of 1,200 to 1,600 feet it is a surprise to ride out upon 

nearly level or broadly rounded surfaces which are deeply mantled with soil. Yellow 

pines (Pinus ponderosa) grow vigorously, but widely spaced, as is their habit; the 

surface is scantily covered with grass, and groups of shrubs stand here and there. 

A few hundred feet to right and left this surface rounds off into steep slopes that 

descend to adjacent hollows. Follow a lateral spur of the ridge and you come to a 

eliff, the margin of a larger mvine. Pursue your course northward along the ridge 

and you ascend easily, though with occasional ~light descent, to .about 4,000 feet 

above sea. Gradually the ascent becomes steeper to the top of a ridge at 5,000 feet, 

and following this two miles to the eastern side of Baldy 1_1ountain you strike a 

. moderate slope of limited extent at about 5,500 feet above sea. Above this Baldy 

presents a serrate ridge whose highest tooth attains 6,432 feet above sea. The 

height, the ragged angular forms, and bare talus all mark the hardness of the rocks, 

rhyolitic porphyry and granite, which occur in a system of large dikes traversing 

hornblende-gneiss. Stormy ~Iountain (7,219 feet), the spur (7,142 feet) 8 miles 

northwest of Baldy, and much of the intervening crest are sustained by similar dikes 

and present the same acute topographic forms, but adjacent to them, at elevations 

above 6,000 feet, there are gently r0unded flattish surfaces, which are physiographically not in sympathy with the active work of frost on the peaks above or the 

energetic corrasion progressing in the ravines ncar by. These flats arc of small 

extent, but of definite character. The most apparent one lies between Twentyfive 

Mile and Lake creeks, where the divide trends north, leaving the dike system of 

rhyolitic porph}'ry that runs out in the sparp pea,k at 7,142 feet. For convenience, 

it may be called Fourmile Ridge. The prevailing rocks of Fourmile Ridge are 

granite and gneiss, which afford no structural occasion for the ftattish surface. For 

a distance of 4 miles the summit has a general elevation above 6,600 and below 6,800 

feet, declining gently northward. It is slightly notched. at several points, and even 

where it widens out it is rounded, not level. But lying as it does between steep and 

c\ren precipitous slopes which descend a thousand feet into the adjacent depths, its 

grassy, soil-covered surface is a striking remnant of an earlier physiographic 

14493-No. 19-03--5 
66 CONTRIBUTIONS TO GEOLOGY OF WASHINGTON. 

condition. It is a derivative from a plam, and although modified it hab not lost 1b; 

significant aspect, a long and practically continuous uniform slope. (See profile 5, 

Pl. XIX.) 

Had the rider, ascending from the Columbia along the old Indmu trail, turned 

southwest on the level ahove the 3,000-foot contour, he might have followed the 

didde between the Columbia and the Entia~, over the hroad hill having·an altitude 

of 3, 757 feet, and out onto the bit of plateau or. mesa which overlooks the junction of 

the two liven;. As may be seen from the topographic map, the accents of the ridge 

are slight, but the wvines carved in its sides are acute. The surface at an altitude 

of about 3, 757 feet, its northeastern and southwestern spurs, and the mesa southea;;t 

of Strummel Canyon are pecmliarly broad and simple forms as compared with thmr 

environment. The mesa exhibits occasional lmsalt :-;carps a.nd is a corner of the 

Waterville plateau isolated l1y' the Columbia Gorge. Through its structural and 

physiographic characters it is an important link between the great plateau and the 

Chelan Mountains. Approaching the mesa in form, hut unlike it in rock structure, 

the hill having an altitude of 3, 757 feet contmues the same topographic phase, and 

its Rpm·s extend the type on the one side to the Entiat Gorge, on the other to Navarre 

Cou]eP. 

Conbidcred as a whole, these feature:-; are clearly distmguishable from the steeps 

which arc now rmbject to energetic con·asion hy brooks and 1 ivulet" Considered in 

detail, two less clearly distinct phat-.es may be recognized among the;;e broader features 

Discriminating by form we may find surfaces which approach a plain and thol:le which 

are marked by moderate relief; judging by relative elevation, we shall discover the 

plainer surfaces above the more dearly sculptured ones, but without definite 

boundaries between them. Carrying the comparisons over wider areas the fiats are 

found at different heights, r;ut always in the same physiographic relations. 

Thul-l, physiographically, the mesa, the spurs of the hill with an altitude of 3, 757 

feet, and .l!"ourmile Ridge belong to one and the same stage. The crests of the hill 

which has an altitude of 3,757 feet, of Baldy, of Stormy, and o£ the hill which has 

an altitude of 7,142 feet, are older monadnocks, whereas the long spur-; of the range 

fall into the class of later features, and the canyons of all rnag·nitudes into that of the 

latest. 

METHOW MOUNTAINS. 

The Methow Mountains lie between Lake Chelan on the southwest and TWI~>P 

and Methow rivers on the northeast. Only their southeastern portion, up to Stat 

Peak, is included in the accompanying map (Pl. XVIII) and in the profile (Pl. XIX). 

A portion o£ it, known as Sawtooth Ridge, extends with serrate and glacier-bearing 

peaks into the heart of the high Cascades. 
U. S. GEOLOGICAL SURVE 'I' PROFESSION AL PAPER NO. 19 PL. XV 

VI EW FROM CHELAN BUTTE, LOOKING N ORTHW EST OV ER LOWER LAKE CH ELAN T O STORMY MOUNTAIN AND NAVARRE PEAKS. 
METHOW MOUN'fAIN8. 67 

At their eastern end the Methow Mountains arc no higher than the neighboring 

plateau east of the Columbia. L1ke the Entiat and Chelan mountain<> thev are 

E.tructurally continuous with the plateau, from which they are separated only by the 

canyon which the river has cut. Looking northward from Chelan Butte or the , 

margin of the plateau above Chelan Ferry, the sky line of the plateau is contmuous 

With that of the Methow Mountains at an altitude of about 3,400 feet. Rising 

westward with moderate grade the peaks of Navarre arc reached, 7,800 to 8,200 feet 

above sea, and thence northwestward for many miles the summits are of remarkably 

uniform altitude 

As a mountain mass between Lake Chelan and the parallel valleys northwest of 

it, the Methow Mountains are 12 to 15 miles across from southwest to northea:-.,t. 

They have a very definite watershed from which all streams flow by the shortest routes 

to Chelan, TwiE.p, or Methow rivers. West of a line drawn north and south about 3 

mileE. east of Navarre Peaks the crest is narrow and often ragged, but high spurs 

extend out on either side to distances of 3 or 4 mile'l, mamtaining m their heights 

the general altitude of the watershed. Navarre Peaks are the southeastern representatives of a large number of points which closely approach or slightly exceed 8,000 

feet in elevation, and which are linked together by high ridges branchmg from and 

on a general level with the central divide. These peaks and spurs are clearly 

derivatives from a plateau. 

The eastern part of the summit exhibits some broad areas, and from them the 

spur& decline gradually, especially toward the southwest. A::; compared with the 

deep canyons cut in them, these surfaces belong to an earlier stage of topographic 

development. They are residuals which distingui::;h the district east of an ideal 

line from the regwn of acutely mature topography west of it. The distribution of 

these residuals and of the drainage hnes flowing southwest and northeast suggests 

that the surface between the Methow and the Chelan east of Navarre Peaks would, 

if restored, form an arch pitchmg southeast and merging in that direction into the 

basalt plateau. Traced westward this arch flattens out in a level above the summit,. 

of the higher part of the range. 

In topographic formE. and drainage the Methow Mountains present mobt 

interesting problems which involve the discussion of earlier topographic phaE.es, 

deformation, btrcarn adJustment, and glaciation. But the writer's opportunities 

for observation have not been sufficient to solve them. 
68 CONTRIBUTIONS. TO GEOLOGY OF WASHINGTON. 

SYNTHETIC DISCUSSION 

GENERAL STATgMENT. 

In the preceding pages the separate features of the reg-ion have been dm,cribed 

as they now are, and their interpretation in terms of topographic development has 

been suggested. In what follows it itl proposed to discuss each stage of that 

development from the earliest recognized up to the latest glacial epoch. The glacial 

phenomena are very conspicuous and have been noted from the terraces of the 

Columbia to the lingering glaciertl of the (i;ascades, but their record iH one which 

i& more eomplex than can be read without special studies which are yet to he made 

Ly an experienced glacialist. That chapter is therefore not included in this 

di:,cussion. 

Enough has been saiJ in the de&el'lptions ~o indicate that several stages of topographic development have been recognized. They are clearly evident in such a 

profile as No. 1, Pl. XIX, from the Entiat Mountains across Columbia Canyon to 

Badger Mountain. Begmnmg with the highetlt, the peak<; (5, 700 to 5,800 feet) and 

the fiat adJacent to them are considered to he repretlentatives of the oldest stage of 

which defimte evidence remains. They are correlated with Badger Mountam, the 

Waterville plateau, surfaeeb in the Chelan and posbibly the Methow Mountains, and 

the level from whwh the high Cascades arc :,culptured. This older,t &tage is therefore 

that of the Cascade plateau, as named by Russell, but now called the Methow stage. 

It is also identified by G. 0. Smith. The characterit-:.tic topographiC type of the 

Methow stage waH a plam, upon which residual hills survived. .Followmg Davir,, it 

may be designated a peneplain, with monadnocks. 

Within this plain were carved valleys which appear to have attained nearly 

mature development That of the Columbm in profile No. 1, Pl. XIX, appears to 

have been 2,000 or 2,500 feet deep and 7 or 8 miles wide. The smaller streams 

certainly developed shallower and narrower valley>-, hut remnants of the Methow 

plain west of the Columbia were few and limited. On account of its preservation in 

the basin of the Entiat, this stage is named from that river. The charactenstic 

topographic form of the Entiat stage i& mature. It occurs as a spur or divide below 

oc,casional residuals of the Methow stage and above feature;, of later stages. 

Within the relief of the Entmt stage there were cut deeper channels, some of 

them canyons of impressive depth, many of them simply mountam ravines. They 

constitute the 111ost marked and everywhere the most characterir,tic featUles of the 

topography of the region. Any large stream might he chosen as exhiuiting the type, 

but probably none shows It 111 various degreetl better than the Twisp, which from its 

junction with the Methow to its source in the Ca~>cades lies in a canyon that varies 

from a few hundred to 4,000 feet in depth, a<; can be seen on the Methow topographic 
GENERAL STATEMENT. 69 

atlas sheet. This stage is aceordingly named Twisp. The characteristic of the Twisp 

stage is a canyon, the typical feature of topographic youth, but the development 

progressed far toward maturity. 

The Twisp stage closed with accumt'1lations of glacial ice, which occupied the 

canyons and in many instances greatly modified them. Rivers overloaded with drift 

filled their channels to gTeater or less extent. Lake Chelan and the terraces of the 

Columbia. near its outlet afford the most conspicuous examples of these phases of 

activity. This stage of glaciation will accordingly be called the Chelan stage.· 

With ·retreat of the glaciers to the highest amphitheaters of the mountains the 

streams began to reexcavate their channels. · The glaciers still lingec and the rivers 

are still engaged in removing drift. To complete the sequence of stages, this latest 

and present one may be designated from a stream which flows from several surviving 

glaciers ,and is clearing its old valley of drift, the Stehekin. 

It is somewhat diffieult to place these several stages in geologic time. On the 

evidence of fossil plants from 'the Ellensburg formation, the Methow plain in the 

Yakima district is post-Miocene. The data are fully presented by G. 0. Smith, and 

the unity of the feature throughout the Cascade Range is discussed by the writer 

under its proper head below. The very long time required to accomplish such 

extensive and uniform leveling appears reasonably to occupy most of the Pliocence 

and to bring the ~ate of the next stage near the close of that epoch. 

· The line between the Pliocene and Pleistocene can not be fixed with certainty. 

By definition Pleistocene begins with and dates from the earliest Glacial epoch. In 

the Puget Sound Basin there are deposits of two glacial advances with those of an 

inter-Glacial epoch, but in the region of glacial erosion and on the eastern side of the 

Cascades generally the observed record is of one advance only. · The relation of the 

repeated record to the simpler one bas not been made out. They may correspond to 

the same time interval, during which in the lowlands of Puget Sound there was tm 

epoch of glacial retreat not marked in the mountains. In that case glaciation of the 

canyons covers the whole time of glaeiation and all glaciation was later than that of 

canyon cutting. In other words, the Twisp stage was pre-Glacial, and. therefore 

pre-Pleistocene. On the other hat!d, it is equally probable that glaciation of the 

heights as now recognized correspoflded only to the later epoch which is recorded in 

the Vashon till of Puget Sound. An earlier epoch of glaciation, that of the 

Admiralty till, in that case occurred also in the Cascades, but has not been made out. 

Its record may not be recognizable if the Twisp stage of energetic erosion corresponded with the inter-Glacial episode. On that hypothesis, the Entiat stage may 

have been early Pleistocene. 
70 CONTRIBUTIONS TO GEOLOGY OF WASHINGTON. 

The following tabulation expresses the most reasonable estimates of correlation 

for the several stages in geologic time. 

Physiographic development of the Cascade Range. 

Physio- I Date, if one un-1 Date, if two or ' · 1 Nature of characteristic 

~~'_r::f_g~-~c_ 1 __ T_y_·p_e_lo_c_•t_li_t)_·. _______ "_c_ti-vi-t)_·. ____ G_\~_~_TJ;~-~t_;c_'b_. :_m_o_:P_e -~~-ac_· ia_l ____ Pe_r_io_d_. __ 

Stehekin . . . . Stehekin sources and 

valley. 

Chelan ...... Gorge of Lake Chelan 

and terraces of the 

Columbia. 

Twisp . _. __ .. Canyon of the '!'wisp, 1\fcthow qundrangle. 

Entiat....... Basin of the Entiat and 

foot spurs of the Chelan 

Range. 

Methow . . . . . Generallythroughoutthe 

broad mountain district, and specilically in Yakima Valley. 

Glacial retreat and reexca- vation of old valleys. 

Glncial occupation of cun- yons1 canyon modification, and valley filling 

by overloaded streams. Glacial diversion of streams. 

General acceleration of cor- rasion, resulting in exca- vation of canyons and 

ravines with readjust- ments of drainage. 

Development of mature topography generally · throughout the Cascade 

plateau. · 

Planation by erosion to a low plain with monadnooks. 

Post-Glacial to Post-Glacial to Recent. 

present. present. 

Glacial epoch .. Latest Glacial 

epoch. Pleistocene. 

Pre-Glacial ..... Inter-Glacial ... 

Pliocene o Pleistocene. 

Pre-Glacial..... Ea~lier Glacial . (Sierran Age.) 

epoch. 

Pre-Glacial ..... Pre-Glacial ..... Pliocene. 

METHOW STAGE. 

CONOITIONS OF JlEVEI,QPMEN'r. 

The chamcteristic feature of the Methow stage was a. plain, and where• now 

reeognized the .essential form of the remnants is a :flat, or ·approaches a :flat, from 

which the existing surface is immediately derived. The plain might have originated 

through (a) marine deposition, (b) marine planation, (c) as the original surface of a 

lava flow, (d) by erosion to a peneplain. 

((t and b) Marine deposition and planation are excluded from among the possible 

conditions of development of the Methow plain, because the surface extended over 

hundreds of square miles without being in any way conformably related to any 

sedimentary formation, and is cut unconformably across the bedding of the youngest 

sediments of the district, the Ellensburg formation. 

(c) The original surfaces of Miocene basalt :flows probably coincide with the 

Methow plain in some areas of the Columbia Basin, and it has been thought that 

these coincidences were so extensive that the plain was determined by the basalt, at 

least as far as the flows extended. The writer's local observations about w· aterville 

and west of the Columbia arc not satisfactorily definite in this regard. At the one 

point where dip of the basalt could be seen in the Entiat Mountains there Is a slight 

unconformity, but generally no good observation was possible. ln the Yakima 

district, however, where the evidence of coincidence was thought to be most striking, 

G. 0. Smith has observed a general unconformity, which, though commonly slight, 

/ 
METHOW STAGE. 71 

is often considerable, and, though the angle of divergence be small, it is sufficient 

to -carry the plain diagonally across the great thickness of the basalts, from older to 

later rocks. Thus in a broad view the unconformity is unmistttk\tble, and the plain 

is not identical with the surface of the lava flows. 

(d) The extent of the Methow plain as observed by Russell and the writer is 

more t~an 10,000 square miles. It has been identified by Russell, Smith, and the 

writer as· a feature cut upon nearly all rocks of the region, the schistose n1etamorphics, ~he Tertiary arkose sandstones, the bedded basalt flows, and the pumaceous 

clastics of the Ellensburg formation. ·These facts are consistent with but one 

interpretation, that of widespread planation by agencies of subaerial erosion to a 

plain approaching base-level. The Methow plain, therefore, represents a flat lowland. The plain has been observed not to agree with nor pass over some summits 

of granite, granite-porphyry, rhyolitic porphyry, and other intrut<ives. These eminences are regarded by the writer as monadnocks, ·which mark a certain degree of 

incompleteness in planation. 

OrUeria of recognition.-The characteristics by which areas of the Methow 

plain are identified are flatness, unsympathetic relation to environment, and relative 

elevation. Flatness is not used in a mathematical sense. No topographic feature 

is a plane, and it is not probable that any area of the old plain survives with 

unmodified sui'face. · An approach to flatness is all that can be looked for. Flat 

docs not mean level. The old plain had indeed a very low slope, but in course of 

elevation to the altitudes at which it is now found-"3,000 to 9,000 feet--it has 

acquired relatively steep inclinations at some places. 

An unsympathetic relation of a topographic feature to its environment is that 

relation in which the feature could not develop or in which the prevailing activities 

are working to destroy it. An elevated flat crowning steep slopes is in an unsympathetic relation to its environment. Less obviously, but not less truly unsympathetic, are long, smooth slopes and spurs subject to attack by streams retrogressively 

developing their channels. In the usual case the unsympathetic feature is a 

residual, which still retains in part a surface developed under a different environment, but where the original surface is all eroded the unsympathetic form may 

still be seen in inherited featm•es or relations. Thus uniform elevation of mountain ·summits is interpreted as inheritance from a plain which was dissected in 

consequence of elevation. The' uniformity is not in sympathy with the height. 

There are, furthermore, degrees of unsympathetic relations. The extreme is that 

existing between a plateau ·and a canyon, between passive age and aggressive youth. 

Of a less degree is the diversity between a wide or rounded ridge crest and slopes 

which approach maturity. And canyons cut. in maturely developed topography 

afford examples of least conspicuous nn~ympathetic relations 
72 CONTJUBUTIONS TO GEOLOGY OF WASHINGTON. 

Relative elevation is an important factor in recognizing remnants of the 

.Methow plain, but in this respect elevation above sea is less significant than 

position above o.ther features. Since in course of physiographic development an 

older residual feature commonly lies above all younger forms, we should look for 

remnants of the plain, the oldest surviving phase, at the greatest altitudes in any 

locality; but where the plain falls below any summit we are constrained to r~cognize 

the. latter as a residual, or monadnock, upon the plain . 

.Distribut·ion and character of residuals.-Dctailed geologic surveying with 

adequate base maps has been carried out· in the Cascade province chiefly by G. 0. 

Smith. His identification of the Methow plain in the Yaldma province is _described 

by him in the earlier part of this paper, to which the reader is rr ferred. In what 

follows the plain is traced in the district between Wenatchee and Methow and in 

portions of the high Cascades seen by the writer. 

The distribution of recognized residuals is shown on the maps, Pls. XVI, XVII, 

and XVIII. The mapping is an adaptation of observation to base map, carried out 

in the office and largely guided by the topographer's delineation of forms. Exact 

boundaries can not be recognized in the field, except occasionally for short spaces, 

and none arc attempted in the graphic statement. The areas delineated as representing the Methow plain are not thought ever to correspond exactly in surface 

with it. They have been modified slightly by eorrasion and materially by disintegration and wind erosion; but they retain the typical charaetcr of the plain 

sufficiently to demonstrate its former existence and to represent it. 

In theW aterville plateau wide areas are characterized by flatness. They oceupy 

the positions of broad divides :1lld are commonly distinguished from lower, gently 

sloping surfaces by an intermediate steeper facet. They are unsympathetic to the 

slightly accented drainage channel:,;, and they fall into one general plain. They 

probably correspond nearly with the surfaee of basalt flows, but no outcrops of the 

roek were observed, deep soil prevailing everywhere within sight of the writer's 

route except on the scarps toward Columbia River. Their great extent removes 

them from the category of snrfaees possibly due to roek strueture only, and their 

other characters identify them as residuals of an ancient lowland plair1 of erosion. 

Two isolated hills southeast of Waterville and the nearby spurs of Badger 

Mountain are believed closely to :tpproach the flat of the .Methow plain. The spur 

east of the main road from Waterville aeross the mountain most nearly continues 

to the summit an unbroken surface, which may be considered representative. The. 

top of Badger Mountain has the character of the Waterville plateau, and long, even 

spurs extend this aspect into the valley of Roek Island Creek on the south. 

Independent physiographic evidenee of Columbia Canyon and some meager 

structural faets show that the mountain is an anticline of later development than the 
R.U.Goode,Geographer in cha rg e 

Triangulation by W. T. Gri s wo ld 

Topography by R.A.Fa rmerand W.T.Gri swold 

Surveyed in 1897- 98. 

PHYSIOGRAPHIC MAP OF .THE SOUTHERN HALF OF THE CHELAl~ QUADRANGLE 

INC LU DING PART OF THE C OLUMBIA PLATEAU, THE C OLUMBIA CANYON,AND 

THE ·E A STERN SPU RS OF T~.E CAS CADE RANGE 

S cal e 

2k============io==================t

2

= =====::::J4 mil e s 

'" ' , ,. c:_ atet.J .11. r-o. U TH. N.Y. 

PROFESSIONAL PAPER NO.I9 

Phys logr&p hy by 

Bail ey Wi llis ,Ge olo gis t 

LEGEND 

:lvfonadnocks on the 

U~owplain 

Areas which in form 

and attitude accord 

nearly!Vith the Methow 

pl ain 

Areas which inform 

and altitude accord 

nearly withfe a tures of the· Entiat stage 

<\reas which exhlbit 

features oftheTwisp 

and late r stages 

6 

Numbers refer to 

sections on-PLXJX 
METHOW STAGE. 73 

:Methow plain, wh10h should accordingly rise above the arch or to a greater or less 

degree coincide w1th it. In general profile the coincidence appears to be elose; the 

r,ununit and southern slopes arc probably not much modified; but the northern :;lope 

is dissected until very little, 1f any, part of the surface represents the plain. 

South of Rock Island Cret>k the characteri~:~tic broad expanses extend to the 

escarpment above the Columbia gorge and their sky lines are continuous across the 

canyon with the height:; of Table Mountain, from which they de::;cend to the Yakima 

Valley. 

The Methow plain we&t of the Columbia 1s preserved in a few small remnants 

only. The even slope on hasalt in the eastern end of the Entiat :Mountains, 4,800 to 

4,900 feet above sea; Ribbon Mesa, 3,300 feet; t-.purs above the contour of 3,400 

feet on the hill, which reaches an elevation of 3,747 feet; and Fourmile Ridge, 6,700 

feet, have all been described. They are topog1aphic :fiats whiCh are on the whole 

not determined by structure planes of the basalt, where there is hasalt, and which 

occur on jointed and schistot>e rocks as well, which are not in sympathy with their 

present environment, and which have, to later topographic Htagcs, the relation that 

the Cascade plain hplds. Therefore, in sp1te of their con'liderable and divert>e 

altitudes, they are identified as residuals of that once continuous lowland. 

Jt Ib posbible that detailed Rtudy of the Chelan Mountains between Baldy 

Mountain, R1bbon Mesa, and Chelan Butte will discover other bits of the plain 

on summ1ts of spurs and about monadnocks. There is room for question whether 

the hill which nses to an elevatwn of 3,757 feet is a monadnock or not. The 

plain may sweep above 1t, but the general mterpretation of facts would not be 

modified in any essential partiCular by such changes in the determinatiOn of local 

poRltlOUb. 

Of the Methow Mountains the writer has not seen the portion east of Navarre 

Peaks except m general views ±rom a distance. The1r profile thus seen is characteribtically that of a tilted, somewhat dissected plain. They rit>e with eontinuous 

hne from the plateau level eabt of the Columbia from 3,400 feet or les;; to 6,000 

feet above sea. They then appear to sweep up in a steeper but moderate grade 

to the heights of Navarre Peaks at 7,800 feet. The topographic map and the 

profile derived from It (fig. ±, Pl. XIX) confirm this observation. Along the 

crest, from 3,400 to 6,000 feet above bea, there are residual surfaces of :fiat form 

unsympathetic to their envuonment. One extends from 3,600 feet to 3,800 feet. 

There is then a 1ise over Cooper Mountam, which is probably a monadnock, 

about 300 feet above the plain. Beyond this the :fiats occur near or above 5,600 

feet, with ascent to 6,100 feet, and thence upward the crest 1s sharp. Navarre 

Peaks might be regarded as bUmmits older or younger than the :fiat surfaces--as 
74 CONTRIBUTIONS TO GEOLOGY OF WASHINGTON. 

monadnocks or descendants;" but, considered in their relations . to the many 

heights of about the same altitude which occur west of them and connect them 

with ~he ,general level of the high Cascades, Navarre Peaks appear to be descendants, and the plain sweeps up to and over them. 

'J'he reconstruction of the Methow plain has proceeded thus far upon identification of residuals, which actually or so nearly represent its surface that they may be 

taken for it. In extending the reconstruction further over the Methow Mountains 

and the high Cascades, another line of reasoning must be followed. 

In the Ca~Scade Range views from high altitudes present two striking features, 

that mutually are in strong contrast. The one is the acutener,;s of the mountain 

forms, often sharply needle-like; the other is the uniformity of general elevation 

which these boldly sculptured peaks ·approach. The sharp foims result from the 

activity of frost and thaw, of con·asion, and of transportation in shattering and 

removing rock masses, whose principal controlling structure is steep jointing. The 

uniformity of heights has been interpreted as inheritance from a former plain surface, and also an effect of erosion at great altitude. 

The latter hypothesis has been considered in view of facts closely resembling 

those observed by Dr. Dawson, its author, in the same mountain range, but it does 

not seem to be sustained. The activities of erosion do not appear to tend toward 

more uniform effects with greater altitude, on the contrary elevation emphasizes 

their locally unequal intensities. Corrasion and transportation are effected by 

falling water,. whose energy for a given mass is directly as the fall, and consequently 

increases .with height of land. Con·asion and transportation are very narrowly 

localized in activity, and hold the same relation to general degradation that a circular 

sa~ ~oes to a planer. Their intense application results in deep canyons, the extreme 

of ·'height and depth. Disintegrating influences, whether chemical or mechanical, 

·may act equally with equal opportunity, but they are controlled by conditions of 

exposure. Upon un uneven surface these are varied and they become more and 

more diverse as inequalities of relief develop. The_suggestion that frost and thaw 

may with elevation gain in effectiveness more rapidly than cormsion and so may 

limit the height to which peaks may attain in a growing range, appears not to be 

sustained by study of mountains much higher than the Cascades, nor by theoretical 

reasoning in regard to the work of freezing water. Thus after careful consideration 

the writer has felt obliged to abandon the hypothesis of development of a common 

high level among mountain peaks. 

The general level of Cascade summits is suggested in the views, Pis. IX and X. 

The one IS the central section· of a panorama of three views, looking southwest 

a A descendant is a topographic feature carved from the mass beneath an older topographic form which has been 

removed. 
U. s·. GEOLOGICAL SURVE:Y 

R.U.Goode, Geographer in cha rge 

Tr iangu lati on by W. T. Griswold 

Topo graphy by R.A.Fa rmer and W,T. Griswold 

Surveyed i n 1897 -98 

PHYSIOGRAPHIC MAP OF THE N ORTHERN HALP OF THE CHELAN QUADRANGLE 

INCLUDING THE C OLUMBIA CANYO N, LOWER LAKE CHELAN,AND THE E ASTERN ., 

SP UR S OF THE CAS CADE RANGE ,WHICHPOR.M THE CHELAN RANGE 

PROFESS!ONAL PAPER NO. l9 PL. XYll 

Physiography by 

Bail e y Willis,Geologist 

LEGEND 

fo nadnocks on the 

Methowplam 

Areaswhlchinform 

and altitude accord 

neartywith the Methow 

plain 

Areas which in form 

and altitude accord 

n early Withfeatures 

. of the Entiat stage 

Areas w h ich exhibit 

features of the Twisp 

and later stages 

a 

Numbersreferto· 

sections on PLXJX 
ENTIAT STAGE. 75 

from th-:; head of a tributary of the Yakima across spurs of the range. The other· 

is a view down Stehekin Valley to the distant Methow Mountains. In neither case 

does the photograph give the full effect of these landscapes; the angle is but 50 

degrees of the full circle, of which the greater part may in a central situation show 

siinilar effects, and in each of these particular cases the camera was 1,000 feet or 

more below the peaks, which consequently ;tppear higher near by. To sec such a 

surface of common altitude the eye should be in it. A diagrammatic presentation 

of the fact of nearly uniform altitudes is given in the profiles of the Methow Mountains west of Navarre Peaks. (Figs. 4 and 5 of Pl. XlX.) Of the dozen or more 

summits represented in as many miles, none is lower than 7,800 feet and only one, 

Star Peak, rises to 8,500 feet above sea. While this diagram gives but a single line, 

several profiles across the range might be constructed showing similar relations of 

mountain tops on spurs which extend 3 to 4 miles from the central divide. 

The fact of uniformity of summit level becomes more and more impressive as 

it is observed over wider and wider areas. Russell and the writer have found it to 

extend over practically all of the high Cascades, occurring at altitudes which vary 

from 6,000 to 8,500 feet according to the portion of the range in view. There will 

probablx be little if any dissent among future observers from the inference that this 

widespread equality of heights is derived from a landscape of gentle relief, but 

· opinions will differ as to the degree of plainness of the ancient surface. The occurrence of granite monadnocks, such as Mount Stuart, rising a few hundred feet above 

the probable position of the old plain, is significant in this connection. VV ere they 

numerous they would indicate a hilly region, but far apart as they are and of moderate 

altitude they suggest that planation had made general progress toward a low peneplain. 

The present altitude, which the plain would have above the mountain tops if it 

existed, i;; yet to be carefully estimated. ln that portion of the Methow Range 

which has been topographically mapped and studied, the summits near and above 

8,500 feet (Star Peak, 8,500; Oval Peak, 8,800) have broad, rounded forms. It is 

possible that they rose to, if not above, the Cascade plain in this vicinity. On the 

assumptionthat the altitude of the plain would now be about 8,500 feet, the inh.erited 

summits lie 200 to 600 feet below it. This is probably a minimum. On the other 

hand, if Mount Stuart and similar granite cones are monadnocks, the plain can not 

well be reconstructed more than 1,200 feet above the ridges which surround them. 

ENTIA'!' STAGE. 

PHYS!OGRAPlllC RELATJONS. 

The physiographic relations which constitute the chief criteria that serve to 

identify features of the Entiat stage are those of a development intermediate 

between an older and a younger stage. In position and in form Entiat residuals lie 

between the flats of the Methow plain and the canyons of the Twisp stage. 
7o CONTRIBUTIONS 'l'O GEOLOGY OF WASHINGTON. 

The Entiat stage was tirst recognized by the wnter m riding from vVenatchee up 

the Columbia gorge and over the high spurs between it and Entiat RIYer. It then 

became evident that the Columbia Valley consisted of at least two parts, an inner 

canyon and an outm valley, a younger and an older phase; and above the older 

were found the snrfaces identified as parts of the Methow plain In extending the 

observations It was found that a distmctwn must hP made between those parts of 

the Cascades which bad been :,;nbJect to much precipitation and con'>eqnently had 

suffered cleep eprrasion, and thm,e which had received slight precipitation and had 

been but faintly engraved. ThiS dlfferennc of sculptm:cs m Entiat time i~ parallel 

w1th the present diverse aspects of eoiT(~~:~ponding a1:cas of great and little ramfall 

The cntena by whiCh Entiat and Methow feature:,; are distinguished haye already 

been stated. "Where they hoth oecm ttdjacently, the former lie helow the latter and 

in unsympathetic relations. The distinguishing point between Entiat and TwiE>p 

slopes is a more or less prominent proief'ting angle or bench Itt, significance 

depends upon the faet that in homogenPou:, material normal profile'> of a continuous 

cyele are concave upward. Tlw curve or anglo which i~'> convex upward or outward 

may result from rock differences or from glaciation or from 1evival of stream 

activity; the first it, ("omnJOnly a local, the others general phenomenon of auv particular district. Along the western side of the Columbia the gneis<. and granite are 

unlike in detail, but in general they are homogeneou~ in their attitude towa1d 

erosion agencies. Tb(~ hill'l }m,~e not been glaciated, nor did gla('iers of the latest 

epoch extend so far down Pitber the Columbia or Entiat Nevertbele;,s, each of the 

_..''''''"""long E>purs of the Entiat and Chelan mountains b ('haracterized by a markedly 

prominent angle, ami in the ravmes a ("orre:,ponding change occurs at the top of a 

E>tcep stream grade or fall. In all the ung-laciated height:,; west of the Columbia, this 

angle i~ a prominent and significant feature. In glaciated ;;lopes the older record'l 

cut hy the stn~ams are modified hy iee work, and the features are mo1e f'omplex 

l>ISTRIBU'l'lON ~N]) liiAILH'T~m OF RE~UHTA!h 

FeatmP~-> sueh as are (\haracteristw of the Entiat ;,tage exi&t generally throughout 

the higher Cascades, so far as the writer's observation goes, hut re:,Jduab, m the 

sense of unmodified forms, probably do not survive to the E>ame extent a-, do those 

of the Methow '-tago, 1f at all. This follows from the greater effecth'encsE> of 

erosion on slope:'l a:, comparPd With that on plains. 

Representative Entiat features a1e rounded or tlat ndge~->, "pur-,, and gentle 

::.lope'>, commonly distmguishcd by a eovermg of deep :,Oil, as well a~ hy their 

physiographiC relations. To enumerate them would be to repeat much that has heen 

&aid in describing tho range.;;, but typical examples may be cited. In the eastern end 

of the Entiat Mountain.,; the spurs, which extend at about 4, 700 feet from the tlat of 
R.U.Goode, Geographer in charge 

Tri an gulatien by A.H.Sylveste r 

Topog raphy by W.T.Gri swold and R.A.Farmer 

Surveyed in 1897 and 1899 

PHYSIOGRAPHIC MAP OF THE S OUTHERN ~F OFTHE.METHOWQUADRANGLE 

INCLUDING M I DDLE LAKE CHELAN, THE METHOW RANGE, 

AND THE METHOWVALLEY 

2 

.JUUU!=i BIEN /!.. CO LITH. N.Y. 

PROFESS lONAL PAP ER NO.l9 

Phys logr&ph y by 

Bailey Wi lti s ,Ge otogist 

LEG END 

.Areas which in form 

and altitude accord 

n e arly with features 

of the Entiat stage 

AreaswhicheKb.ibil 

features oftheTwisp 

a nd later stages 

8 

Numb eri; refer to 

sections on PLXIX. 

N ote: The v a lley of' 

JtfetlwwRiverismodii'UiL 

bygl.aciat ULn. t.o s uchan.. 

extent -that in:f'erence.s 

can not .:~afe ~y drawn. 

f'rorn the map.As f'ielil 

observation.:;· ended with 

theMetJww R ange, th.e 

?"'alley is not; included 

in. the a..rt!as in:terprett:d 
ENTIAT STAGE •. 77 

Methow date down to about the contour of 2,600 feet, exhibit typical Entiat profiles. 

(See profile 1, Pl. XIX). The ridge isolated by Lake Chelan, Columbia River, and 

.Knapp Coulee is a characteristic Entiat form in its summits and spurs above the 

1,500-foot contour. (See profile 2, Pl. XIX.) The rocky height of Chelan Butte is 

probably a monadnock of pre-Methow date, but the development of Entiat features 

ha;; gone so far as to remove the plain from about it. The slopes of the ridge are 

scored by numerous ravines, in which corrasion has progressed steadily during all 

the time since the Entiat epoch elosed. They are therefore more deeply cut than 

formerly, having steeper grades toward the top. In their lo"'Yer channels they have 

been materially modified by deposits of the Chelan glacial epoch. 

The profile 3, Pl. XIX, exhibits Entiat slopes in relation to the forms that 

preceded and followed them. The long spur between Mad Creek and Tyee 

Mountain, 3,500 feet to 6,500 feet; the spur of the Chelan Mountains, 5,500 feet to 

6, 700 feet, and those of the Methow Mountains above 6,000 feet, along this section 

line, are reasonably near Entiat features. They exhibit the long concave curve, the 

windgaps, and the rounded summits, for the most part deeply soil covered. 

There may be features whose age is indeterminate because their aspects and 

relations are capable of more than one interpretation. Such a one is the flat spur 

contoured by the 3,000-foot line west of Navarre Coulee and rising by gentle grade 

to the mountain which has an altitude of 3, 757 feet. If of Methow date, it is a part 

of the plain marked out around the last-mentioned mountain near the 3,500-foot 

contour, and its inferior position is due to warping. If of Entiat date it is a low level 

of an early epoch in the widening of Navarre Valley; and in that case, also," it may, 

in consequence of warping, now occupy a position lower than it had in relation to the 

Chelan Mountains. \V ere the ridge continuously broad and gentle of slope from 

the mountain having an elevation of 3,757 feet nearly to the top of the Chelan 

Mountains east of Baldy, the former date would seem probable; but the hill crowned 

hy the 3,500-foot contour and several interruptions of the gradual slope by steeper 

intervals indicate that the plain was eroded, and we have to deal with an Entiat 

surface which locally developed a flat feature. 

DEl+REI~ OF ~JN'l'IAT HELIE~'. 

West of the Columbia the differcncel:l of elcvtttion covered by features assigned 

to the Entiat stage arc considerable: In the eastern portion of the Entiat.;Monntains, 

from 2,600 feet to 4, 700 feet; in Chelan Butte, from 1,600 feet to 3, 700 feet; in the 

district west of Navarre Coulee, from 2,000 to 6,000 feet; in Tyee Mountain, from 

3,500 to 6,600 feet; in profile across Lake Chelan from Fourmile Ridge to the 

Methow Mountains, from 6,000 to 7,700. These variations occur not only in 

different places, but on slopes which decline in different directions, and some part 
78 OON;I'RIBU'l~IONS 'l'O G EO LOGY 0]' WASHINGTON. 

of the apparent relief is attributed to deformation. \V e may therefore distinguish 

between those which apparently have not and those which have been. tilted. 

The spur which descends at the eastern end of the Entiat Mountains eonnectioi a 

well-preserved Cascade flat with the g·orge of the Columbia, the largest st1·cam. 

Lying on but parallel to an axis of uplift, its inclination has uot been affected 

appreciably by warping, and its relief-2,100 feet~may fairly be taken as 

representing the facts at that place in Entiat time. '{'he spurs of the Chelan 

Mountains extending north from Fourmile Ridge and those of the Methow 

Mountains opposite them are apparently onee continuous parts of a profile now 

interrupted by Chelan' Canyon. . They do not exhibit evidence of depression or 

tilting toward the canyon, and their degree of relicf-1, 700 feet-is probably not 

greatly different fro!n what was the maximum in Entiat time at that point. 

The long slopes which rise 3,000 feet and more to Tyee Mountain and to the 

Stormy Mountain ridge are apparently not in their orig-inal attitude. The elevations 

of Cascade residuals and the eanyons cut in these ranges show that the 'heights of 

Tyee and Stormy are due in part to local as well as to general uplift, and that 

the Entiat features have shared in the change of attitude. In a less degree this is 

believed to be true also of the Chelan Butte ridge. 

GLACIA'l'ED ASPEG'TS OF ENTIAT HEIGHTS. 

· ·where extended masses occur at high altitudes in .the Cascade Range, the 

togographic features may be classed as four in number: (1) Dominant peaks, usually 

acute in . form; (2) high serrate ridges and spurs, which are often very narrow; 

(3) elevated amphitheaters of characteristic glaciated form; (4) canyons, usually also 

glaciated. Those dominant peaks which riioie approximately to a common altitude 

or higher are considered to be descendants of the Methow: plain and its monadnocks, 

as already stated. Similarly, but even less adequately, the serrate ridges and glacial 

amphitheaters represent features of the Entiat stage. They are developed in masses 

whieh were not deeply cut by canyons of. the Twisp stage, but those masses may 

probably have been sculptured into valleys and divides during the Entiat stage. 

The alternative is to assume that degradation of the Methow plain to post-Chelan 

aspects of glacial sculpture was accomplished without any intermediate stage of 

·aqueous erosion. This view possibly might resonably be held were not the Entiat 

stage Clearly recognizable in the unglaciated area. Since the latter is the case, how- a • 

ever, it is logical to infer the development of valleys and ridges of Entiat date, from 

which glaciated amphitheaters and their tangent aretes are derived. 

MATURITY OF ENl'IAT TOPOGHAPHY. 

In the usual threefold division of a topographic life period into youth, maturity, 

and old ag·e, maturity may be used in either one of two senses, namely, to describe 
U, &. GEOlOGICAl. SURVEY 

En1iat Range. Columbia Valley. Badger Mou ntain. 

Monadnocks. Methow Plain. 

1. PROF ILE ACROSS THE COLUMBIA VALL EY ALONG THE EN T IAT-BADG ER MOUNTAIN FROM WEST B Y NORTH TO 

EAST BY SOUTH. 

2. PROFILE ACROSS THE BADGER MOUNTAIN UPWARP, THE WATER VIL L E DOWNWARP, AND THO. CH ELA N UPWA RP FROM SOUTH TO NORTH. 

Wenatchee Valley. Entiat Range . Entiat. Methow Plain. 

3 PROFILE FROM WENATCHEE VALLEY TO CHELAN RANGE ACROSS TH E ENTIAT UPWARP AND TH E WATERV I LLE DOWNWARP TO TH E CH ELAN UPWARP, AS SHOWN BY TH E 

ALTITUD E OF THE METHOW PLAIN F ROM SOUTH BY EAST TO NORTH BY W EST, 

Methow Range . 

PROFESSIONAl. PAPER NO. 18 PL. XIX 

PHYSIOGRAPHIC PROFILES 

WENATCHEE-CHELAN DISTRICT 

CASCADE RANGE 

By Bailey Will is 

Deduced from Unit e d States Geological Survey 

Topogr aphic Maps and F ield Observations 

VERTICAL AND HORIZONTAL SCALE 

er::=cio===="""= =::iz..,.....,.,;3i:=~4;,....,~s~=,;6~"""'~7===8~!!1E!~9 miles 

4, PROFILE ALONG THE CR EST OF TH E METHOW RANGE FROM NORTHWEST TO SO UTHEAST, EXHIB ITING FEATURES ENTIAT STAGE CUT IN T HE M ET HOW PLAIN . 

Mount Tyee. Entiat Valley. Chelan Range . Lake Chelan. 

5. PROFILE ACROSS THE CHELAN AND METHOW UPWARPS FROM SOUTH BY W EST TO NORTH BY EAST. 
EN'l'IAT STAGE. 79 

a long mid-interval during which the prevailing features are narrow divides, steep 

slopes, and V valleys; or, second, to designate with precision that exact date at which 

a given residual of an earlier stage is reduced to nothing and the divide begins to 

dwindle under the attack of opposed headwaters. In the latter sense maturity at 

any particular date is a term of stricti}• local application, since residuals do not all · 

succumb at one time. 

In the broader sense of the word, Entiat topography was mature where precipitation was heavy. In the narrower sense, it approached maturity about residuals of 

the "Methow plain, where they still exist, but generally outside the arid region it had 

passed the precise instant of mature development. That is to· say, the divides had 

become sharp and lower than the corresponding surface of the Methow plain. 

ENTIAT FEATURES IN A.RID AREAS. 

In arid areas Entiat features have not been clearly recognized; This fact may 

be due to one of two conditions. In Entiat time areas now arid and high may have 

been similarly situated, or they may have been low. In ~he one case aridity, in the 

other lowness, would have limited erosion, and the features which developed would in 

either case be inconspicuous. 

In the Yakima district G. 0. Smith does not distinguish the Entiat stage. On 

the Waterville plateau and Badger Mountain it is probable that Entiat features exist, 

but are mantled by later deposits and obscured. The valley of the Columbia bounds 

these areas on the west. Its inner and outer goq{es are less conspicuously separate 

east of the river than west of it, because landslides have generally lnodified the scarp, 

and to them the suggestive details of the profile might be ascribed; but the two 

episodes of development are distinguishable on the east in appropriate relations to 

the corresponding details west of the .river. On the plateau there occur, below 

residual flats of Methow date, long spurs separated by lightly engraved channels. 

Their contours and profiles are round and gentle. They appear nowhere to be cornposed superficially of hard rock. Soil derived from basalt and a soft sand deposit of 

unknown age and origin were the materials seen. Well-filled angles and fluent curves 

of the landscape evidence wind work. The sculpture is that of aqueous erosion, 

moderately developed, and later modified by wind erosion and wind-drifted material. 

In view of the sta~es elsewhere found, it is probable that the work of aqueous 

agencies was accomplished during the Entiat and Twisp epochs, and that effects 

of mantling are due to conditions which prevailed during the Chelan and Stehekin 

(Glacial and post-Glacial) stages. 

On Badger Mountain ravines are cut more deeply than on the plateau and winds 

have had comparatively little effect; yet the slopes of the niountain ex,hibit remarkably slight erosion as compared with the heights west of the Columbia. It will be 
80 CONTRIBUTIONS TO G EO LOGY OF W .ASHINGTON. 

shown in discussing deformation that the elevation of Badger Mountain above Waterville plateau is chiefly a growth of post-Entiat date, and therefore E~tiat features 

are inconspicuous on the mountain, and what dissection bas occurred there is of 

Twisp age and later. 

TWISP STAGE. 

CHARAC'I'BRISTIC FEATURES. 

Canyons are the prevailing valley forms of the Cascade province. In elevated 

districts they are profound and numerous, and, having the U section due to glaciation, their volume represents a large part of that of the original uplifted mass. 

Between the glaciated and arid districts lies the zone of simple but energetic aqueous 

erosion in which unmodified canyons are most strikingly developed. In the arid 

region, the central plateau of Washington, canyons are deeply cut in the basalt. 

The most conspicuous, such as Grand Coulee, are ascribed to diversion of the 

Columbia during glacial time, and if that be true, do not belong to the stage here to 

be discussed. 

The inner gorge of the Columbia between Wenatchee and Methow is a steep-sided 

channel cut below older topographic features in the bed rock mass of the region. 

Its position and proportions are such in relation to the river that there can be no 

doubt that the master stream cut it out. Glacial strire were found by Salisbury 

on its western wall just above Chelan Ferry. A morainic terrace occurs on the eastern bank a mile below Chelan Falls, and from this southern limit of the glacier a 

very conspicuous system of river terraces, composed of glacial drift, extends down 

the valley. The gorge is, therefore, of aqueous origin and was carved prior to the 

latest glacial episode. As such it is a representative canyon of a pre-Glacial stage. 

It lies within and clearly distinct from features ascribed to the Entiat stage, and its 

development thus occupies an interval of time between the Entiat epoch and 

glaciation. 

A geographic name for this stage can not well be chosen from this typical 

section o~ the Columbia Gorge, the desirable names having been applied to other 

uses, but it would appear from the topographic map of the Methow quadrangle that 

Twisp River has worked out a channel scarcely less characteristic, and the name is 

selected accordingly. 

D~JVELOPM~JNT OF TOPOGRAPHIC FORMS. 

The Twisp cycle of topographic development was interrupted at an early phase 

by the advent of glacial conditions. The survival of Entiat and Methow residuals 

and the effects of glaciation sufficiently demonstrate this fact. 

Columbia Canyon, between W enatchec and Chelan, was cut to its present depth by 

aqueous corrasion before the latest Glacial epoch, since it is occupied by drift, which 

the river has removed down to bed rock at various points along its channel. The 
CHELAN STAGE. 81 

canyon walls receded to some extent during Glacial and post-Glacial time, and the 

amount of recession is shown to be appreciable by the fact that cliffs above Chelan 

Falls, past which a glacier extended and over which it rose, now exhibit pinnacled 

profiles that have developed since the ice withdrew. But the occurrence of glacial 

stri.re near the summit and on the river side of the cliffs indicates that the form of 

the canyon was not greatly different then fro~ what it now is. This is within less 

than 2 miles of the end of a tongue of the wide-spreading glacier which call}e 

from Methow and Okanogan districts. The ice was probably nearly stagnant and 

ineffective. 

In the glaciated region of the higher Cascades, the canyon:; are developed on a 

grand scale. Russell has rightly described them as extending with channels at 

railroad grades into the very heart of the mountain mass, and they are from 1,000 

to 3,000 feet in depth. They have been widened and deepened by ice work, to 

what degree is yet to be determined, but apparently in some instances greatly. 

Nevertheless, when all reasonable allowance has been made for glaciation, the 

canyons which may be ascribed to corrasion during the Twisp stage were of great 

depth. They were relatively narrower than they now are, and their topographic 

development had the character of advanced youth. 

CHELAN STAGE. 

CIIARACTER OF THE RECORD. 

The climatic conditions of the Chelan stage interrupted the topographic cycle of 

the Twisp stage. They induced glaciation, and occasioned very pronounced phenomena of glacial erosion and glacial construction, the latter including extensive 

deposits from overloaded streams. Russell has already described these features in a 

preliminary way, and they ·have been touched upon incidentally in this article. The 

general facts are conspicuous, have been widely observed, and are published. It is 

expedient here to discuss only.one fact, the depth of Lake Chelan, which has a possible 

relation also to the question of deformation. 

'l'HE BASIN OF LAKE CHELAN. 

Lake Chelan occupies a canyon in granitic and gneissoid rocks. The waters are 

retained by a dam of drift, but discharge through the gorge of Chelan River into the 

Columbia, whose bed is not far from solid rock. According to the altitudes above 

sea of rock in place in the Columbia several miles below the junction, that of the 

lowest rock sill over which the waters of Lake Chelan can have escaped is about 700 

feet. The ele\ration of the lake's surface is 1,079 feet, and its depth exceeds 1,000 feet 

through a stretch of 16 miles. a The maximum sounding was 1,419 feet, i. e., to 340 

a Sounded by l\Ir. W. G. Steel, at request of l\Ir. Henry Gannett, for the United States Geological Survey. MS. records. 

14493-No. 19-03-6 
82 CONTRIBUTIONS TO GEOLOGY OF W.ASHING'l'ON. 

feet below sea level, or 1,040 feet below the rock rim of the basin. The depths are 

given on the map (Pl. XVII), and they present an interesting problem in the 9uestion, 

How did the lake channel become so deep? 

According to the physiographic record, the Chelan channel developed by stream 

robbing and became a river canyon through the usual effects 

which are, however, incompetent to have so greatly deepened it. 

deepened by faulting or glacial erosion. 

of stream action, 

It may have been 

Faulting is not readily capable of direct proof or disproof in the rock structures 

of gneiss and granite. There is, however, throughout the Chelan-Stehekin system 

of channels a unity of form, which strongly suggests unity of development, and 

through which any hypothesis of faulting as a condition of the Lake Chelan canyon 

should be extended to its tributaries; but the ramifications of the system and the 

slenderness of the supposed downthrows are such that the hypothesis is untenable. 

If the area of faulting be restricted to that of excessive depth in the Chelan Basin, 

there is a similar peculiarity of form in the supposed downthrow and no evidence to 

support the proposition. We may turn, then, from the purely theoretical idea of 

faulting to that of glacial erosion. 

Effects of glacial erosion are obvious throughout the Chelan-Stehekin system. 

They m~y be traced from the moraines of existing glaciers in the ci'rques about the 

headwaters, down the grooved and rounded canyon walls, into the waters of Lake. 

Chelan, and out to the terminal moraine near the Columbia, in all a distance of 70 

miles. Three miles above the terminus of the ancient glacier its thickness was 1,000 

feet, and its surface stood about this amount above the present level of Lake Chelan. 

Thirty miles above its lower end, that is, near Safety Harbor Creek, the thickness of 

the ice was 4,500 feet, and toward the head of the lake it probably exceeded 5,000 

feet. Detailed observations as to the upper limit of glaciation along the lake shore 

are needed, but the above statements are. based upon a, few pojnts definitely n'oted. 

That this mass of ice was capable of exerting great erosive power can scarcely be 

doubted, but it remains to be shown that the phenomena of depth of the lake basin 

bear some logical relation to the probable effects of ice corrasion. 

It is believed ~hat the erosive power of ice when moving as a g·lacier is a function 

of the volume of ice, the restriction of channel, and the rate of flow. a These factors 

are, it is true, in a measure interdependent, but it is not important here to separate 

their influences, as we can n<:!t deal with the problem quantitatively. It will suffice 

to show that the excavation of the channel is proportioned to the amount of ice 

entering from successive tributaries and that, where the volume is constant, the depth 

of the channel is inversely as its width. 

-~-- ~-~--- ~----~--- --- ------~-

. a Personal communication with G. K. Gilbert. 
DEFORMATION. 83 

The extent of former glaciers in the Chelan-Stehekin system is indicated (with 

a rough approximation only to the facts, but sufficient for this purpose) in the map 

(Pl. VIII). It may the~·e be noted that the drainage from a considerable area is 

concentrated at the junction of Stehekin and Bridge creeks, and it is at that point 

that the headwater canyons pass into a conspicuously wider channel, and that the 

stream assumes a flatter grade. .Just above the junction of Agnes Creek this flat 

ends in· an abrupt descent to a wider and lower valley floor, which extends from 

Agnes Creek to the hcad~of Lake Chelan. The eross section of the canyon widens 

slightly, but not notably, and its depth, so far as it may be determined by the soundings in Lake Chelan, increases gradually to the junction of Railroad Creek. Abreastof this stream the valley is considerably wider, and may be regarded as a basin competent to store a considerable volume of icc. A short distance down the lake, near 

Prince Creek, is the upper end of the Narrows, which extend to Twentyfive Mile 

Creek. Here the walls of the canyon are steepest, and approach each other most 

nearly, and here the depth of the lake increases rapidly. Below Twentyfive Mile 

Creek the valley opens out and the lake basin rapidly shallows. 

There is in the above-described relations that coincidence between width and 

depth of channel which in the single case might be considered fortuitous, but which, 

when oft repeated and found to be systematic, presents a strong argument for a 

relation between cause 'and effect. ·while the data are by no means so complete as 

might be wished, and while a thorough discussion of the problem would require that 

one should eliminate the effects of glacial and stream filling in order to arrive at a 

true measure of the depth of the channel, it is not probable that these subordinate 

factors could change the dominant relations frorri which it is inferred that the basin 

of Lake Chelan owes its unusual depth and character ehiefl.y to glacial e·rosion. 

A further test of this conclusion may be applied by contrasting it with other 

valleys in the same region, many of which have been occupied by glaciers, " and none 

of which exhibit similar peculiarities. A ~boroug-h study of . the glacial effects 

throughout the region should shed much light upon the nature of the phenomena, 

but it may here suffice to say that the Chelan case is exceptional (1) in the large 

volume of ice contributed from an area of approximately 350 square miles, throughout which the mountain summits range in altitud!=l from 7,000 to 8,500 feet, and 

(2) in the remarkable depth and muTowness of the canyon through which the glacier 

was forced. 

DEFORl\1A'I'ION. 

Oriteria.-The criteria according- to which the. nature and amount of deformation are commonly determined are of a stratig-raphic character. The surface of 

a stratum, assumed to have been plane and observed to be flexed, is a datum from 

which changes of form may be deduced. In the area under discussion in the present 
84 CONTRIBUTIONS TO GEOLOGY OF WA~HINGTON. 

case the rocks are gneisses and intrusive granites, whose structures do not afford 

dips from which to infer the nature of recent deformatil).n. The occurrences of 

basalts, which do afford such data in the Ellensburg district, are of no value in the 

area west of the Columbia and north of the 'Wenatchee, as their distribution is 

very limited. Jointing, the commonly developed structure of all the rocks of the 

district, bas not been so studied as to yield results. It follows that deformation 

must be investigated upon a different basis, viz, chiefly upon physiographic evidence, 

through the warped form of the earliest recognized topographic surface, the Methow 

plain; and the facts described in the account of the physiographic history are thus 

made use of in the following discussion. 

Fwulamental proposi#ons.-ln the preceding discussion certain principles ha,,.e 

been applied in interpreting the relations of physiographic features and deformation, but the statement of those principles has been d!'lferred to this place, where it 

may form an introduction to the account of mountain growth. In general terms the 

pi'opositions are as follows: ' 

(1) Mountain growth involves changes of altitude of such vertical amount and 

such moderate extent as compared with continental areas that elongation of the 

earth's radii beneath t.he mountain mass may -more plausibly be assumed to account 

for the elevation reached above sea level than general subsidence of the datum 

piane. The effect of such elongation is appropriately described as an uplift when 

the whofe mass is eonsidered. 

(2) Uplift results in deformation of the preexisting topographic surface, which 

is elevated in some areas above others that may be considered relatively depressed. 

In what follows the term warp will be used to designate deformation of the surface, 

upwarp and downwarp being employed to describe, respectively, elevated and 

depressed areas, always the former topographic surface, and independently of the 

rock structure. The latter is appropriately expressed in the terms anticline and 

syncline. 

(3) Erosion occurs only as a result of ehange of relative altitude, and its effects 

arc a function of the amount of change. 

{4) Other things being equal, the several sections of a river valley between 

source and mouth are consistently developed, when uplift has been uniform and 

simultaneous, within moderate limits of variation. Ineonsistent sections arc 

evidence o£ unequal uplift or of uplifts of different dates. 

(5) At any particular stage of development in homogeneous rocks the normal 

grade, or slope, of a plain or river valley is variable within narrow limits only; 

abnormally steep, gentle, or reversed grades are effects of \Varping during SUCCeeding cycles'. 
DEFORMA'l'ION. 85 

CASCADE Ul'LU'T. 

The Cascade·Range is an elevated mass which is observed by all who come within 

sight. Equally recognizable by adequate observation is the wide, tabular form of 

its surface, as are also the marginal slopes which connect it with lower adjacent 

surfaces. The gross form, all details of spurs and sculpture being omitted from 

consideration, is that of a broad uplift, with wide, flat top and sloping flanks. 

•The general fact that the uplifted surface has been eroded is obvious, and 

investigation of the topographic forms shows that they express several stages of 

development, of which the initial one was an ancient peneplain that extends over the 

mountain mass. The peneplain having been practically flat and low, according to 

its origin, and being now elevated in part, there has been warping, the amount and 

character of which are expressed in any section by the difference between an arc of 

the earth's spheroid at sea level and the flat arch of the uplifted surface. Thus we 

may describe the Cascade uplift as that broad and flat-topped elevation which lies 

between Pug~t Sound on the west and the central plateau of the Columbia River 

Valley on the east. 

Height and extent.-'Vith reference to sea level, the surface of the Cascade 

uplift, or1he upwarp, actual and restored, varies in altitude from 6,000 to 8,500 feet 

throughout the area of its upper level. The maximum of 8,500 feet is attained 

probably north of the forty-seventh parallel and is rpaintained throughout more than 

one degree of latitude to the forty-ninth parallel. South of the forty-seventh parallel 

the extent and altitude of the warped plain are not well known, except that at an 

altitude of about 7,500 feet it forms the platform upon which stands the volcanic 

cone of Mount Rainier, and probably extends in a similar manner beneath Mount 

Adams, Mount Hood, and other volcanoes in Oregon. Its altitude probably lessens 

toward the south, but it is not likely that it falls below 5,000 feet along the broad 

axis of the uplift. The width of the uplift at its elevated plateau level is variable, 

but is probably rarely less than 60 miles nor more than 100. As may be seen in Pl. 

I, the eastern margin is crenulated, and in consequence of the fluting the width 

of the flat top of the upwarp is very variable, and it is possible, as suggested by 

Smith, that the larger marginal downwarp may extend nearly across the axis or 

entirely across it. 

The further description is limited to the area north of the forty-seventh parallel 

and more_ narrowly to the regions which have been described in detail in the 

preceding chapters. 

Limits of Cascade 7tpwarp.-The limits of an upwarp are here taken to be 

represented by those slopes produced by warping, by which the descent from the 

high, flat top to adjacent areas is accomplished, without regard to effects of erosion. 
86 CONTRIBUTIONS 'l'O GEOI,OG Y 0.1!' WASHINGTON. 

In this sense the Cascade upwarp is limited on the north, according to the observations 

of G. 0. Smith, apparently by a slope which extends across the axis of the range a 

short distance north of the forty-ninth parallel and leads down to a lower surface 

south of the Frazer River, but still high above the canyon of that stream. On the 

west, south of the forty-ninth parallel, according to Smith, the plateau of the 

upwarp extends, at an elevation of 5,000 feet, under Mount Baker, and thence 

descends to the Sound level by a monoclinal flexure. A degree of latitude farther 

south, northeast of Seattle, its western margin lies farther east. In the vicinity of 

Index, on the Great Northern, at the town of Snoqualmie, and along Green and 

White rivers, north of Mount Rainier, the descent from the mountain summits, 

at elevations of 6,000 to 7,000 feet, to that of the gravel plateau of the Puget 

Sound Basin is so abrupt as to suggest a fault scarp. There is no positive evidence 

·of a fault as yet known, and the alternative hypothesis of glacial erosion has at least 

equal value at the present time. Beneath Mount Rainier and possibly to some 

dis'tance west of that peak the upwarp maintains an altitude of 6,000 to 7,000 

feet, and it appears in this latitude, just south of the forty-seventh parallel, to attain 

an 'expansion comparable to that which it has along the forty-ninth parallel. 

The eastern limit of the Cascade npwarp may in general ·be described as !L slope 

which stretches in a direction south by west from the vicinity of Osoyoos Lake, o~ 

the forty-ninth parallel, to Ellensburg, and thence southerly along the west side of 

Yakima Valley, across the Columbia, into Oregon. This general statement of the 

position of the slope must, however, be qualified by the description of marginal 

flutings, which extend nearly at right angles to the major uplift far out into the 

adjacent plateau on the east and give to the axial upwarp an extremely irregular 

form. 

The area of the upwarp thus described covers approximately 5 square degrees 

.of the surface north of Columbia River, equivalent to about 20,000 sguare miles. 

Its further extent in Oregon bas not been determined, but it is probable that it is 

Bqual to that in Washington. 

MARGINAL FLEXVRES. 

The eastern· slope of the Cascade up warp north of latitude 46° 30' has been 

studied physiographically by G. 0. Smith and the writer with sufficient care to 

determine several margin:;tl flexures, whose axes trend, in general, northwest and 

southeast; that is, nearly at right angles to the broad majo1· axis of tho upwarp 

itself. A statement of these features, so far as they may be deseribed by the writer 

follows, with a brief account of the evidence according to which eaeh is recognized. 

Methow downwarp.-Metbow River is one of the larger tributaries· of the 

Columbia, which it enters about midway between the Okanogan and the Chelan, in 

latitude 48°, longitude 120°. The geneml trend ?f the Methow Valley is south by 
CASCADE UPLIFT. 87 

east. Its headwaters are near the forty-ninth parallel, and are opposed to those of 

Paysaytcn River, which flow northerly. On the east is the Okanogan Range, and 

on the west the Methow, hoth of which are of great altituue. The elevation of the 

Methow above sea at its junction with the Columbia is 750 feet; at the town of Methow 

it is 1,158 feet, and at Winthrop, 30 miles :from Methow, along the Htream, it is 1,'765 

feet. ·winthrop is situated at the principal forks of the river, aud above this point 

the grade of the stream rises more rapidly. The aspect of the valley at the present 

stream level varies, according to the rocks in which it is carved. A lower secHon, 

cut in schists, is narrow and canyon-like; an upper section. comprising most of the 

stretch between Methow and Winthrop, is excavated in softer Mesozoic rocks, and 

the valley floor is wider. lt bas been occupied by a glacier, which has left extensive 

deposits. especially along the river channel. From those conditions of diversity of 

rock structure and interaction of stream and ice work, it :follows that the physiographic aspects of the 'alley are not simple, and that it presents a problem in 

sculpture which can be fully solved only by earefnl observation on the ground. 

That observation has not been had, and the inferences which follow arc based upon 

distant views from the Methow Mountains, study of the Methow atlas shePt, and an 

interpretation consistent with that of phenomena of adjacent regions. 

Above the valley bottom of Methow River, between Methow and Winthrop, 

many hills rit->e to an altitude of about 4,000 feet above Rea, and they are thought to 

represent a former level, which theoretically may he that of the Methow Valley 

bottom reached during the Entiat stage or may represent the older Methow 

peneplain. If the former be the case, the corresponding level of the Methow plain 

would lie at an p.ltitude above 4,000 feet, an amount which may be deduced from 

the depth of the Columbia Valley at the close of the Entiat stage. The maximum 

determined for that valley is about 2,100 feet, as observed in the Entiat Monntaitm: 

There is no reason to suppose that the Methow has made nny cleeper excavation than 

the Columbia. Indeed, the inferenee would be rather the other way. Hence the 

position of the Methow penepl~tin in the Methow Valley is not far from 6,000 feet 

above sea, provided the general uniformity of hilltops at 4,000 feet represents the 

bottom of the Methow Valley in Entiat time. On the other hand, the 4,000-foot 

level may stand for the Methow plain, and, if so, it would coincide by gmdnal slope 

with the general altitude of that plain in the Columbia River Plateau to the southeast. 

Whether the level of the Methow peneplain in the Methow Valley be 6,000 or 

4,000 feet above sea, it is lower than that of the plain on the adjacent Okanogan and 

Methow mountains, its place in the former being probably not far from 8,000 feet, 

and in the latter not less than 8,500 feet above sea. Hence it seems reasonable to 

regard the Methow Valley as a downwarp resulting from deformation of the Methow 

plain. 
88 CONTRIBUTIONS TO GEOLOGY O.E' W .ASHINGTON. 

11fetlww 1pwarp.-Southwest of the Methow Valley, in latitude 48°, is a great 

mass of mountains known as the Methow Mountains. In it are sunk the canyons of 

the Twisp and Lake Chelan, and it extends westward into the highest part of the 

main Cascade Range. Its area may be estimated at 1,000 to 2,000 square miles, 

according to the limits which may be arbitrarily drawn between it and the central 

Cascade upwarp. This mountain mass is designated the Methow upwarp. 

The Methow upwarp is defined not only by existing topographic features, but 

by the altitude of the Methow peneplain and the slopes which it has assumed. In 

general, where most elevated, the Methow plain has an altitude of 8,500 feet, 

coincident with the crest of the Methow Mountains. On the east the surface 

descends from Navarre Peaks to the Methow and Columbia, sloping from a probable 

altitude of 8,000 feet to that of 3,500 or less. Toward the northeast the surface 

slopes to the position of the plain in the Methow Valley. On the south the descent 

is from an altitude of 6,000 feet to that of 3,500 feet. The southern margin is 

complicated by a much smallm• feature, the depression within which lies the lower 

end of Lake Chelan, and south of which is the uplift forming the Chelan Range. The 

upwarp of Chelan Mountains is, in fact, a spur of the Methow upwarp, with which 

it is continuous along Fourmile Ridge and across Lake Chelan at the Narrows, as 

shown in profile. 

The rocks of this uplifted mass, so far as they have been observed by Russell 

and the writer, consist of ancient schist, together with intruded granite, quartzdiorite, and similar igneous rocks. They afford no structure significantly related to 

the present upwarp, unless it be vertical jointing. The cleavage which they exhibit 

is probably of much more ancient date. Considered in detail, there are marked 

differences in structure and texture, which constitute elementFJ of heterogeneity; but 

considered in mass the whole is remarkably homogeneous. The northern and 

western portions of the upwarp do, it is true,- include areas of Mesozoic sedimentary 

rocks; but they may be considered as, incidental, rather than characteristic, since 

they arc quite subordinate in area and volume. 

The evidence of the Methow upwarp being thus limited to physiographic 

phenomena, it is found first in the altitude of the Methow plain, whose position has 

already been described. By reference to the sections on PI. XIX, it will be seen 

that it is. essentially flat-topped and connected by gentle slopes with the position of 

the plain on three sides. Further evidence is found in the effects of con·asion, 

especially as exemplified in the canyons o:f Twisp and Chelan rivers, which are 

among the most profound and most sharply cut of the entire Cascade Range. That 

of the Twisp heads near the junction of the Methow uplift with the main Cascades, 

where the elevation of the flat surface is about 8,500 feet, and ~escends rapidly to its 

junction with the Methow at 1,600 feet. The greater- part of this descent of 7,000 
CASCADE UPLIJ!'T. 89 

feet is made in the first lO miles, and the canyon thence to its mouth is flat-bottomed. 

It is clearly the product of retrogressive activity of the stream working headwards 

against the slope of the upraised mass west of Methow River. The upper course 

of the stream is along the axis of the uplift, and there is a sharp bend by which . . 

the river turns, as it were, down the slope. toward the Methow. It .is possible 

that this change of direction iH significant of an episode of capture in the history 

of the Twisp, which may formerly have flowed on in a continuous southeasterly 

course toward Libbey Creek; but no adequate study of the topographic forms 

has been made to determine that such was the fact. The development of the 

Chelan Canyon has already been described, and it has been shown that the relations 

between its several parts and to the old channels of Knapp and Navarre creeks are 

best explained as results of the opportunities for piracy which were provided by the 

growth of the Methow upwarp. The open valley of lower Lake Chelan is inconsistent in topographic phase with the great canyon above Twentyfive Mile Creek, 

and the inconsistency is regarded as evidence of the vigorous elevation from which 

the youth of the latter section follows·. The mature aspect of topographic forms 

about the lower section of Lake Chelan, and the beheaded character of Knapp and 

Navarre coulees, are facts which show that the Lower Chelan region was relatively 

depressed a;,; the Methow upwarp rose. 

OlMlan B1dte upwctrp.-South of Lake Chelan, and between it and the westwardtrending course of Columbia River, is the striking eminence of Chelan Butte, 

.having an altitude of 3,892 feet. The summit of granite dikes and schist is considered to be a monadnock, rising perhaps 400 feet above the Cascade plain. Thence 

westward extends a ridge having an elevation of 3,000 to 3,500 feet, which rises 

to the summit of Baldy Mountains, 6,432 feet, and continues northwestward in the 

Chelan Mountains, of which the culminating summit is Stormy Mountain, 7,219 feet. 

The heights of Baldy, Stormy, and other acute peaks which are largely maintained 

by outerops of quartz diorite, are believed also to represent monadnocks above the 

Methow plain, the altitude of which is somewhat above 6,000 feet. South of this 

elevated ridge the Methow plain is recognized in the vV aterville plateau at an elevation of 2,800 to 3,000 feet, that is at least 500 feet below its probable position on 

Chelan Butte, and is noted in Ribbon .Mesa and in the hill rising to an altitude of 

3, 757 feet at 3,000 to 3,500 feet, or about 3,000 feet below its position about Stormy 

and Baldy mounta~ns. This difference in altitude of the Methow plain is taken as 

representing the slope from the axis of an upwarp which corresponds with the trend 

of the Chelan Mountains from Stormy east by south· to Chelan Butte, and which 

divides the basin of the Lower Chelan from that of the Vvaterville plateau. The 

peculiar physiographic relations of Knapp and Navarre coulees arc interpreted as 

cfferts of this upwarp, across which the streams held their respective courses until 
~0 CONTRIBUTIONS TO GEOLOGY OF WASHINGTON. 

they had cut deep canyons, but by which they were ultimately retarded until they 

were beheaded by the Little Chelan, a tributary of the Columbia north of the axis. 

Waterville dowri.warp.-The Methow plain. is ver.v clearly preserved in the 

Waterville plateau and Ribbon Mesa, the latter lying west of Columbia River at 

a general altitude of 2,800 to 3,000 feet. The Methow .plnin is lowest, so far as 

observed, where it is represented in two small mesas southeast of Waterville, at an 

elevation of 2,800 feet, and from this least altitude it rises northward, westw~trd, and 

southward as would the surface of a shallow spoon. This depression, which is 

recognized solely on the evidence of the deformed Methow plain, is an embayment 

between the Chelan Butte upwarp and that of Badger Mountain, and, like the basin 

of lower Lake Chelan, is a minor crenulation of the margin of the Cascade upwarp. 

Badger JJ:fmmtain ttplij~.-Badger Mountain, cast of the Columbia, has already 

been described as a broad, low elevation of the Columbia Plateau.. vVest of the river 

its axial continuation is the Entiat Mountains, which, extending northwestward, 

lie between the headwaters of Entiat and Wenatchee rivers. This line of mountains, although divided by the canyon of the Columbia, is a continuous zone of 

uplift, highest toward the northwest, and sinking southeastward into the level of the 

central plateau of Washington. Along this summit the Methow peneplain is recognized in Badger Mountain at an altitude slightly above 4,000 feet; in the eastern end 

of the Entiat Range at 4,800 to 5,000 feet; 10' miles ,farther northwest, about Cougar 

Mountain, at 6,000 feet; and near the headwaters of the Entiat at. probably 6,500 

feet. These are maximum elevations, from which the plain slopes away to the northcast down to the vV aterville plateau and Ribbon Mesa, already described, and to the 

southwest into the valley of the Wenatchee. Adjacent to the W enat<:.hec Canyon its 

probable altitude is not far from 4,000 feet. On the evidence of the relative altitudes 

of the old plain, the Badger-Entiat axis is recognized as a zone of local uplift. This 

inference is sustained by an examination of the canyon of the Columbia, and its relation 

to the Col urn bia Valley of the Entiat cycle, as appears from a comparison of the depth 

of the canyon abreast of Badger Mountain with that below Chelan Butte, and the relative altitudes of the old valley floor in the corresponding positions. The fall of the 

Columbia at the present time from Chelan Butte toW enatchee, a distance of 25 miles, 

is about 15 feet, and may therefore be left out of consideration, the river being taken 

as a level datum. The depth of the canyon below the older valley at Chelan Butte 

is 800 feet, and abreast of Badger Mountain is 2,000 feet; th~t is to say, the old valley floor is 1,200 feet higher above the practically level river bed 25 miles farther 

downstream. As the river can not be supposed to have flowed up this slope, it is 

evident that the valley floor has been raised 1,200 feet more at the Badger Mountain 

axis than it has south of Chelan Butte. This relation demonstrates the ability of the 

antecedent Columbia River to maintain its course across the rising uplift. 
EPISODES m' DEFORMATION. 91 

Wenatclwe dowmoarp (lnd 1pwarp.-The "\Venatchee Valley, like the Methow, is 

floored in pa:t by sedimentary rocks which are more easily eroded than the schist 

and granite and basalt of adjacent districts; and as it has been deeply eroded by 

both ice and wate;r, its physiographic features are complex. It is inferred that it 

corresponds to a downwarp having the form defined by the contours, and that it is 

limited on the southwest by the Wenatchee upwarp. The broad, evenly sloping 

surface of the latter is thought to represent very closely the Methow plain. 

EPISODES OF DEFORMATION. 

I'RE-TERTIARY DEFORMATION. 

The latest effects of deformation, those which have been described and which 

are of late Tertiary and post-Tertiary date, are but the most recent of a number of 

moVBments whose history within the Cascade province no doubt goes back to the 

earliest geologic events that can there be recogni7.ed. It would not fall within the 

scope of this article to discuss pre-Tertiary movements, even were adequate data 

available, but it is desirable to point out that each of the major downwarps of 

post-Tertiary time corresponds in position with a synclinorium in which pre-Tertiary 

sediments were deposited. Cretaceous strata occur in the Methow downwarp, and 

Eocene deposits arc extensively developed in the vV enatchee and Yakima downwarps, whereas on the intervening upwarps the rocks are very much older. With 

regard to the Cretaceous, 've can not say that the limits of geographic distribution of 

the sediments correspond with the depression which developed later. Indeed, the 

Cretaceous rocks extend across the northern part of the Cascade upwarp, where they 

occur upturned to dips of 90 degTees. The basins of Eocene strata, on the other 

hand, were of local character, and apparently do conespond somewhat closely to 

the respective downwarps in which they are found; but this is not true, as pointed 

out by G. 0. Smith, in regard to the Miocene of the Yakima Valley. Rocks of 

Miocene, Eocene, Cretaceous, and earlier ages had suffered compressive stress and 

been folded during more than one epoch of deformation before the beginning of 

that late Tertiary topographic cycle during which the Methow peneplain developed. 

From these faets it is apparent that the post-Tertiary" deformation mis not .a 

peculiar effect initiated in a region previously little disturbed, but was merely the 

successor of other effects to which it may be genetically related, in so far as a common 

cause may have acted in this province from an early geologic date. 

This is an expression of a fact- which is of general occnrrence so far as the 

writer's observation goes, namely, that a region of orogenic movcmen't has commonly 

been the scene of repeated mountain growths widely separated in ti!ne. The reverse 

(that there are extensive provinces in which mountainous elevations have not developed) is also true, and the facts thus point to persistence, intermittence, and localiza· 

tion of the causes of orogeny. 
92 CONTRIBUTIONS TO GEOLOGY OF WASHINGTON. 

TERTIARY AND POST-TERTIARY DEFORMATION. 

All that follows relates to deformation which is later in time of occurrence than 

the planation of the Methow peneplain. The effects as a whole might be summed 

up in the phrase the growth of the Cascade Range. The general effect is the uplift 

of the mass from which the Cascade Mountains are carved, and the details have been 

described in preceding paragraphs. 

Through a study of the physiography, and particularly of the Columbia River 

Valley above Wenatchee, two episodes of deformation have been distinguished, the 

first being that which occasioned the Entiat cycle of physiographic development, the 

second that which gave rise to the Twisp cycle. Referring to the table of physiographic development, it will be seen that these may both be considered pre-Glacialthat is, pre-Pleistocene-if the glacial conditions of the Cascade Range be found to 

have been restricted to a single episode; or the Entiat and Twisp cycles may both 

fall within the Pleistocene if two or more glacial episodes ~hould be recognized; 

The writer inclines to the belief that the latter interpretation is correct, the reasons 

being that the condition of planation reached during the Methow cycle was probably 

such as to require most of Pliocene time for its development, and, further, that there 

is distinct evidence in the drift deposits o£ Puget Sound of two well-separated 

glacial invasions. Thus it seems probable that both episodes of growth of the 

Cascade Range fall within the Pleistocene division of the Quaternary. 

It hSts been pointed out by G. 0. Smith that effects of npwarping and downwarping, which in the Yakima Valley may be regarded as effects of Twisp date, 

correspond to anticlines and synclines that developed before the Methow plain 

reached its last phase. Smith does not in his area recognize the Entiat stage, and 

no comparison of effects of that stage with others is made by him. In the region 

north of the ·wenatchee, however, it seems probable that upwarps and downwarps 

which were moderately developed durin~ the Entiat cycle were greatly accentuated 

during the Twisp cycle, and that there wa::- practical coincidence of the axes of 

elevation and depression during the two diffe1·ent episodes. Thus the Columbia 

·Valley across the Entiat-Badger Mountain upwarp is deeper for each of the two 

cycles than the corresponding valley south of Chelan Butte, and it follows from this 

fact that the axis of upwarping was well marked in the earlier as well as in the later 

stage of deformation. Many of the facts of physiographic development which have 

already been adequately discussed point in the same direction. 

CAUSES OF DEFORMATION. 

DIRECTION OF STRESS. 

Granting that theoretically stress may be exerted Ill the earth's crust from any 

direction, it is convenient to discuss effects of stress as due to vertical or horizontal 
CAUSES OF DEFORMATION. 93 

components, ·which are thus taken as being those forces that have given rise to 

deformation; and in what follows there is a tacit assumption that we have to deal in 

this particular case with effects either of vertical ~tress or of horizontal stress, one 

or the other and not both. 

Vertical stresses appear at first sight more probably to have been the effective 

causes of vertical uplift than horizontal stresses, and the imagination appeals to the 

intrusion of deep-seated batholiths of granite beneath the elevated mass of the 

Cascade Range. In doing so it can point to pre-Eocene and Miocene intrusions·of 

granite within the area; it may emphasize the fact that the :principal: monadnocks . 

above the Methow plain arc of granite Mount Stuart .. being the most striking and 

important example, and from thc•occurrencc of granite within the areas of upwarps 

it may argue a coincidence of intrusion with uplift.· The: last-named point is, however, in a measure invalidated by the fact that the oceurrence of granite beneath the 

later sediments which lie in the downwarps can neither be affirmed nor denied. 

Again'!t the hypothesis that the deformation of the Cascade Range is due to vertical 

stress, and possibly to batholithic intrusion, are the generally observed facts that the 

rocks everywhere exhibit phenomena of jointing and flexure due to compression 

and that folds in the bedded basalts of the Yakima Valley are even overturned. 

Tur~ing to consider the effects of tangential or horizontal compressive stress, it 

is desirable to distinguish two classes of effects, one of which may be known as competent structure, the other as incompetent structure, involving shear or flow. Competent structure is exhibited in an elevation of stratified rockR such as is commonly 

described by the term anticline. It is developed under conditions that direct the 

effective component of the stress in the direction of bedding. At any point of change 

of dip the stress is resolved into two components, one of which continues in the farther direction of bedding, and the other acts radially to elevate the stratum with the 

load resting upon it. The requirements of development of the structure are those 

of an arch capable of supporting the superincumbent load; and the proportions of the 

structure are limited accordingly. From these considerations it follows that anticlines raised under the law of competent structure arc relatively narrow.a 

The horizontal extent of the Cascade uplift is so great as compared with its 

height that if regarded as an arched structure it is exceedingly flat. Its width varies 

.from forty to sixty times its height; and it is clear that no section of a body of rocks 

thus extending over two or three scores of miles can be looked upon as self-sustaining. It follows that the elevation of the range as a competent structure can not be 

considered. 

The development of incompetent structure by compression results in shortening 

the mass in one clirecti~n, or in two directions; with corresponding- elongation of the 

«Willis, l\Iechanics of Appalachian structure: Thirteenth Ann. Rept. U.S. Geol. Survey, pt. 2: Van Hise, Principles 

of pre-Cambrian geology: Sixteenth Ann. Rcpt. U. S. Geol. Su,;.ey, pt. L 
94 CONTRIBUTIONS TO GEOLOGY OF WASHINGTON. 

other dimensions, or of the third dimension. The change of volume, if there be any, 

is assumed to be negligible; that is, in considering this type of deformation the volume is taken to be constant. The strain may be that which is described by Becker 

as a simple shear," or that which Van Rise denotes. by the term pure shortening.D 

The distinction lies in the internal structures developed within the mass, the change 

of form as a whole being the same in either case. 

It has been shown by Becker, through mathematical analysis,c that dividing 

planes develop through simple shear in elastic brittle masses at ang·les approaching 

45 degrees to the dii;ection of stress, and this theoretical conclusion has been abundantly substantiated through experiment. On the other hand, Van Rise and Hoskins 

have shown that in case a rock mass has been made to flow in a direction of least 

resistance, cleavage planes are develop.ed in a normal attitude to the direction of 

stress. The structural change is apparently one involving min.nte movements upon 

many parallel planes, accompanied by the rotation of already existing mineral 

particles and the development of new minerals whose longest axes arc pai·allel to the 

direction of flow.· This structure develops only in the zone of flow and gives rise to 

"flow cleavtlge." Shear, as described by Becker, may occur in ·any rigid mass, in 

the zone of flow or in that of fraCture; in the zone of flow it does not correspopd 

with flow cleavage; in the zone of fracture it may give rise to independent ''fracture 

cleavage" or jointing·. 

The structural phenomena of the Cascade Range are illustrated in the two views 

of Pl. XX, which were both taken within a mile of Cascade Pass at the head of the 

Stehekin. In A the cliff rising above the lake exhibits near the center of the view a 

number of inclined joint planes, which are sufficiently well marked to have determined 

the courses of the rivulets descending from the slope above. No exact observations 

of the dips of these planes are available, but they appear to lie at such an angle to the 

horizontal as possibly to come within the limits assignable to the attitude of shearing 

planes or :fracture planes. They may be hypothetically regarded as effects of shear 

developed in the zone of fracture through a horizontal compressive stress. In 

Pl. XX, B, a nearly vertical cleavage structure is clearly exhibited in the details of 

topographic forms. It is that structure which if dominant in the heart of the Cascade 

uplift, and so far as macroscopic, examination shows it has the characteristics assigned 

by. Van Hise•to cleavage developed in the deep zone of flow. The inference which 

may, with some assurance, be drawn from its widespread occurrence is that the mass 

of the Cascades wm.; deformed while that portion now exposed in the highest peaks . was still very deeply buried.a 

a Finite. homogeneous ~train, flow, and rupture of rocks: Bull. Gcol. Soc. America, vol. 4, p. 22. 

bl'rinciples of North American pre-Cambrian geology: Sixteenth Ann. Rept. U.S. Geol. Survey, pt. 1, p. 636. 

c Ibid., p. 30 ct seq. 

dFor rehttcd observations see Spurr,J. E., Ore deposits of Monte Cristo, Washington: Twenty-second Ann. Rept. U.S. 

Geol. Survey, pt. 2, pp. 801-802. 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER NO. 19 PL. XX 

A SOUTHERN SLOPE OF BOSTON MOUNTAIN , SHOWING INCLINED JOINT PLANES. 

H. PINNACLES SOUTHWEST OF CASCADE PASS, SHOWING VERTICAL JOINTING, 
CAUSES OF DEFORMATION. 95 

Flow cleavage and fracture cleavage structure have a common origin m compressive stress. The observed structures in the Cascade Range occur generally 

throughout the mountains, and can not be separated according to locality. They 

may perhaps be distinguished by date. H it should be found that the fracture 

cleavage developed in the zone of flow cleavage, the two may be assigned to a common episode of deformation, the date of which must be set so far back that the 

cleaved rocks were exposed through erosion before the development of the Methow 

plain; that is to say, to a pre-Pliocene date. On the other hand, it may be that the 

_fracture cleavage or jointing was predominantly developed in the zone of fracture, 

and must be assigned to a date at which the rocks that it now traverses were nearer 

the surface than they had been when the flow cleavages were formed. In this case 

the relation of the inclined jointing to the pre-Pliocene cleavage may be such that 

the shearing can be attributed to that compressive stress which is thought to have 

caused the elevation of the Cascade mass as it is now observed. This is the conclusiOn reached by Spun·. a 

DIMENSIONS OF THE CASCADE BT,OOK. 

The speculations of the preceding paragraph in regard to the depth at which the 

structures may have developed naturally lead to consideration of a problem which 

may be stated thus: What may have been the depth of the prism which in consequence of compression horizontally was so elongated vertically as to produce the Cascade uplift. There are many qualifying factors, the data for which are incomplete 

or wanting; numerical results, therefore, can at best indicate only an order of magnitude, yet nevertheless there may be profit in stating the conditions of solution. 

Stripped to its purely mathematical form the problem is: Given a prism, supported in isostatic equilibrium and subjected to strains in consequence of which its 

width, length, and height arc changed, but without change of volume; and given "the 

width before and after strain, the ratio of lengths before and after strain, and the 

amount of vertical elongation, to calculate the original height. 

Through the courtesy of Mr. Georg·e F. Becker the following mathematical 

analysis is given: 

UPLIFT BY HORI:lONTAL COMPRESSION. 

The original dimensions of a b~ock are x, y, z, where y is vertical. 

As a result of strain the dimensions become x', y', z', and the volume remains 

constant. 

Let x'=ax and z'=f3z, then y'=L. aft 

«Twenty-second Ann. Rept. U.S. Geol. Survey, pt. 2, p. 802. 
96 CONTRIBUTIONS TO GEOLOGY OF' ,WASHINGTON. 

In a given case suppose that we know 

x' 

-=·a and y'-y=b· X ' ' 

Then, 

y'-y=y'-a f3 y'=y' (1-a f3); 

So that 

,_ b 

y -1-af3 · (1) 

Here y' may be estimated on various hypotheses: 

A. If f3=L or if there is no strain in the directi01i of z, (1) gives 

y'=~ 1-a (2) 

B. If the strain is the same in the directions x and z, (1) gives 

y'=-L 1-a2 (3) 

C. If the strain is the same in the directions y and z, 

1 1 a (3={3, so that f3= viX and (1) b~comes 

y'- b (4) ·1-~a 

To apply this general formula to the special case of the Cascade uplift we may 

approximate to x, the original width, on the warped surface of the peneplain; may 

~ 

FIG. 2.-Diagram of a block. 

measure x', the present width, as the distance 

from the western to the eastern base of the 

uplift at sea level; and may determine the 

amount of vertical elongation as the mean 

elevation of the warped surface above sea 

level. 

The complete form of the upwarped surface not having been worked out, it appears 

best to express, between rather wide lim1ts, 

the relations of the width x before strain to 

the present width x'. According to an estimate based on measurements of the 

warped surface from Columbia River over the Methow Mountaws, the width on 

the warped surface must exceed that on the sea-level line by more than onetenth of a mile in a hundred miles, and this may be taken as the least possible 

ratio of x to x'. Whereas, on the other band, this ratio probably does not exceed 

2 miles in 100, since the width on the warped surface is an arc A C B and is 

considerably shorter than the distance A D E B, which, if the mean height be H 

miles, is 3 miles. The altitude of the Cascade upwarp being about 8,500 feet over ;1 

large area, a mean height of 1t miles is probably a reasonable estimate. In lat1tude 
CAUSES OF DEFORMATION. 97 

41° 30' the present width of the uplift on a sea-level line is close to 100 miles. 

Thus, to obtain a preliminary approximation to the possible limits of the depth of 

the strained mass we may introduce into the equations: x=100.1 and 102; x'=100; 

b=1.5, all values being miles. 

Table of estimated depths of strained mass of the Ca8cade ttplift, calculated and arranged to .~how the r•robable 

limits according to the three equations, which express different conditions of strain. 

---~-- --------------------------------------

y'= 

_-\. 

y' = b 1-a . -------~-----

x=lOO. 1 x=102 

Values· of y' in miles. 

B 

y' = b 

f-a 2 

c 

b 

l-v'a 

·------------- -----------

X=lOO.l x=102 x=100. 1 x=l02 

-----~-· ------1--------------------·--

1, 500 75 750 37.5 15,000 150 

---'----- __ i -------------------------

The results umler C may be discarded, since the equation y' = 1 ~bva is based on 

the assumption that the elongation is the same in the directions of y and z; but z is a 

horizontal dimension at right angles to x, and the observed facts of deformation show 

not only that there has not been elongation of z; on the contrary, there has been 

shortening. The shortening in the direction of z is less than that in the direction 

of x, however, and therefore equation B does not exactly apply; but the strain i.s 

expressed by the general equation y'=1 _baJ3' in whieh B is less than a and greater 

• 

than 1.· If all the assumptions be valid, and if they cover the conditions of strain,. 

the depth of the strained mass should lie between the extremes of B and A-that is, 

it should be more than 37.5 miles and less than 1,500 miles. 

0 

:=~-- ----------------------------~- ~ ------------------------- - - -----0 -,..._ 

FIG. 3.-Diagrammatic section of a deformed mass. 

If these limits appear to be so far apart as to leave the estimate little value, the 

writer would point out that the least depth indicated carries the base of the prism 

down into the zone of rock flow, below that superficial film inwhich the strength of 

rocks, as we know it, is a factor in transmitting stresses sufficient to cause orogenic 

movement. The inference is that a cause of the Cascade uplift (and presumably of 

related quaquaversals) is to be found in compressive stress acting on materials below 

the outer crust; the superficial movements, both vertical and horizontal, may then 

be incidental results of deep-seated strains. 

14493-No. 19-03--7 

' 

INDEX. 

Page. 

Agnes Creek, topography of region near .. .. .. . . .. .. . . 83 

Andesite, occurrence of................................ 18 

Arid areas, Entiat features in.......................... 79 

Badger Mountain, a residual of the ·Methow plain.... 72 

o]titudeof......................................... 49 

character of. ........ _. .. . .. .. .. . .. . . .. .. . . . . .. . .. .. 90 

location and general features of .... _ ..... 51,52-53,79-80 

Badger Mountain uplift, description of _.............. 90 

B~tker, Mount, Cascade platcrm near.................. 31 

Baldy Mountain, height of ............................ 62,89 

rocks and topography of........................... 65 

Basalt, occurrence and character of. ... 11, 12,15-17,50,64,84 

Becker, G. F., cited on deformation................... 94 

mathemrttical an.alysis applicable to Cascade 

uplift furnished by ............................ 95-96 

Boston Mountain, view of, plate showing............. 94 

Calkin•, Frank C., aid rendered by.................... 10 

Campbell, M. R., references to ...................... · .. 35,47 

Cascade lowland, deformation of...................... 39 

extent and development of. ....................... 26-28 

period of development of.................. .. .. . .. . 28 

remnants of, i<l.entificatioi:J. of. ............... 24-26,27-28 

Cascade Mountains, canyons in, features of ....... ~... 81 

drainage of........................................ 9 

elevrttion of. lack of uniformity in, cause of....... 29 

physiographic problems in, stream evidence be~tr- ·~ 

ingupon....................................... 32 

Cascade Pass, views near, plates showing ............. 54,94 

Cascade peneplrtin, hypothesis of...................... •12 

Cascade plateau, age of. ...... :........................ 47 

dissection of, variations in ........................ 30-32 

history of.......................................... 12 

remnants of. ............ ---~........................ 48 

uplift forming, chamcter of .............. _ ........ 29-30 

Cascade Range, age of ........................ _........ 10 

deformation of.. ........... : ....................... 85-91 

geologic formations of .. .. .. .. .. . .. .. . .. .. .. .. .. .. . 11 

glaciation"in....................................... 19 

origin of ........................................... 10-12 

physiographic development of, table showing . . . . 70 

structure of ........................................ 10-11 

summit level of, uniformity of . . . . . . . . . . . . . . . . . . . . 75 

summits of, views of. ............ _ ................. 74-75 

"ystem of antecedent dminage in, identification of. 34 

uplift of central portion, character of .............. 34-35 

views of.. .. . .. .. .. .. .. . .. .. .. .. .. . .. .. . . . .. .. 50, 54, 66, 94 

views from, features of ............................ 74-75 

Cascade uplift, h~ight of............................... 85 

horizontal extent of .................. : .. ....... 85-86,93. 

marginal flexures of ............................... 86-91 

mathematical analysis of.......................... 96 

strained mass of' estimated depths of ...•..•..... '. 97 

Page. 

Chelan Basin, drainage of............................. 61 

glaciation in ....................................... 59,60 

rocks of . .. .. . . . .. . .. . . . .. . .. . . .. .. .. . . .. . .. .. .. .. .. 60 

Chelan Brook, locrttion and drainage area of.......... 61 

Chelan Butte, age of................................... 77 

height of. .......................................... 77,89 

physiography of ................................... 50,77 

view of, plate showing .. .. .. .. .. .. . .. . .. .. .. .. .. .. 60 

views from, plates showing ........................ 64,66 

Chelan Butte up warp, description of .................. 89-90 

Chelan Falls, glaciation near.......................... 80 

Chelan, Lake, b11sin of, depth of, theories to explain .. 82-83 

basin of, features of ................................ 81-83 

description and ·geologic history of. ............... 58-63 

divide between Lake Creek and ................... 62-63 

drift dam at ....................... ·.. .. .. .. .. .. . .. . 58 

elevation and depth of ....................... : .... 81-82 

geologic features of region near ............ _...... 60 

glacial ice at, thickness of......................... 82 

glaciation nertr .................................... 59,60 

physiographic features of Columbia gorge correlated with features of .. .. .. .. .. .. .. .. .. . .. .. .. 60 

Narrows of, location of ............................ 59-60 

Narrows of, plate showing......................... 62 

rocks near.. .. .. .. . .. .. . .. .. .. .. .. .. .. .. . .. . .. .. .. . 60 

views of, plates showing ........................... 62, M 

Chelan Lake Basin,. lower part of, physiographic history of ......................................... 58-61 

upper part.of, physiographic history of ........... 61-63 

Chelan Lake-Wenatchee River district, drainage of.. 53 

Chelan Mountains, physiography of.. ................. 65-66 

Chelan quad_rangle, northern half of, physiographic 

mapshowing ... : ..................... :........ 74 

southern half of, physiographic map showing..... 72 

Chelan Ran"gc, character and position of.............. 59 

Chelan River, historical events of..................... 53 

Chelan stage, rtge of. .. . .. .. .. .. .. . .. .. .. . .. .. .. . .. .. .. 70 

records of, character of............................ 81 

characteristics of . .. . .. . . .. . .. .. . .. .. .. . .. .. . .. .. .. 69 

Chelan-Stehekin drainage system, glrteiers of. ........ 82-83 

Chelan-Stehekin River, source and course of ......... 58,63 

Cleman Mountain, landslide topography of........... 23 

Clealum Ridge, structural relrttious of .. .. .. .. .. . .. . .. 20 

topographic characters of .. .. .. .. .. .. .. . .. .. .. .. .. 20 

Clealum River, course rtnd character .of............... 38 

Coberly Creek, topography at head of................. 52 

Columbia River, elevation of.......................... 49 

glacirttion along ................................... 80-81 

gorge of, features of .............................. 49-51 

gorge of, features of, correlated with tho•e of Lake 

Chelan......................................... 60 

gorge ol, glaciation in • • .. • . . .. . .. . . .. .. . .. . . . .. .. . 80 

99 
. 100 INDEX. 

Page. 

Columbia River, peaks near ........................... 49-50 

plateau marked by·................................ 51 

tributaries of, topographic aud other features of .. 53-63 

Columbia River Canyon, history of. ................... 80-81 

physiography of ................................... 49-50 

wttlls of, recession of .............................. 80-81 

Columbia River lava, description and history of. ..... 11-13 

Columbia Valley, twofold character of................. 76 

view of, plate showing . .. . .. . .. .. . .. .. . .. .. .. .. .. . 64 

Cooper :Mountain, character of . .. .. .. .. .. .. .. . .. .. .. .. 73 

Davis, W. M., references to ............................ 47,68 

Dawson, G, J\I., reference to........................... 74 

Deformation, causes of. ........ · ........................ 92-97 

diagrams illustrating .............................. 96,97 

discussion of ....................................... 83-97 

episodes of ......................................... 91-92 

fundamental propositions concerning....... . . . . . . 84 

post-Tertiary, evidence of.......................... 92 

pre-Tertiary, evidence of .......................... · 91 

Tertiary, evidence of.............................. 92 

Easton schist, age, character, and occurrence of . . . . . . 14 

Ellensburg formation, age, character, and thickness of. 17-18 

Ellensburg quadrangle, area, location, and features of. 9 

basalt interbe.dded with saiidstone in............. 17 

geologic map of portion of........................ 18 

physiographic sketch map of portion of........... 26 

structural features of .. . .. .. . .. . .. .. .. .. .. .. . .. .. .. 21 

Ellensburg sandstone and Yakima basalt, contact of, 

Jigure showing................................. 27 

Entiat Mountains, altitudes attained by............... 49 

physiography of .. .. . .. . .. .. .. .. . .. .. .. .. . .. .. . .. .. 64 

Entiat relief, degree of ................................ 77-78 

Entiat River, description and history of ............... 55-56 

diversion of........................................ 64 

features of history of.. . .. .. .. .. .. .. . .. .. .. .. . .. . .. . 53 

ol<l channel of..................................... 56 

Entiat slope, line of demarcation between Twisp 

slope and .. .. .. . .. . .. .. .. . .. .. .. .. .. .. . .. .. .. .. 76 

Entiat stage, age of .................................... 69,70 

features of, in arid areas ............................ 79-80 

lirst recognition of.:............................... 76 

glaciated remnants of.............................. 78 

physiogqtphic relations of ............... : ......... 75-76 

position and form of .............. · ................. 68,75 

residuals of, distribution and character of. o. ...... 76-80 

topog."aphy ol, maturity of ........... · ....... · ...... 78-79 

Entiat Valley, physiography of. ....................... 55-56 

Eocene rocks, folds in . .. .. .. .. .. .. .. .. . .. . .. . .. .. .. . .. 20 

occurrence and character of ............... , ....... 15-16 

thickness of. ............ ,.......................... 39 

Farmer, R. A., reference to work of................... 49 

Fourmile Ridge, Chelan Mountains, age of formation 

of.............................................. 66 

height of........................................... 73 

physiography of .......................... .' ........ 65-66 

rocks of. ...................................... :.... 65 

Geologic history, summary of .......................... 21-22 

Geologic structure, features of ..... , ................... 19-21 

Gilbert, G. K., references to ........................ 34, 36,47 

Glacial ice, thickness of, at Lake Chelan.............. 82 

thickness of, at Safety Harbor Creek . . . . . . . . . . . . . . 82 

Glaciers of Chelan-Stehekin system, former extent of. 82-83 

Gold Creek, view from head of, plate showing........ 50 

Granite, occurrence of .................. · ............... 60,65 

Granite-porphyry, occurrence of .............. :. . . . . . . 60 

Granodiorite, occurrence and character of............ 15 

Griswold, W. T., reference to work of................. 49 

Hawkins formation, age and character of............. 14 

Page. 

Hayes, C. W., reference to............................. 47 

Hornblende-gneiss, oceurrence of..................... 65 

Hoskins, L. M., cited on rock flowage................. 94 

Hypersthene-andesite, occurrence of.................. 18 

Icicle River, character of.............................. 32 

. Igneous rocks, occurrence and character of. .......... 14-15 

Kittitas Valley, features of ............................ 24-2~ 

Knapp Coulee, features of .......................... 56-57,61 

history of ................................. :. .. . .. .. 57 

Knapp Creek, diversion of, by deformation . . . . . . . . . . . 61 

drainage area of .................................. : 61 

Knowlton, F. H., determinations of fossil plants by ... 17,47 

Lake Creek, divide between Lake Chelan and, height 

of ................... ~ .......................... 62-63 

Landslides, occurrence of .............................. 23,51 

Lava, basaltic,,occurrence of.......................... 50 

Lavos, eruptions of~-····-······--······-·············- 11,18 

:Manastash formation, occurrence and chnracter of . . . 16 

Mascall formation, correlation of ...................... 17-18 

Methow down warp, description of .................... 86-87 

J\Icthow Mountains, area of............................ 67 

character and position of.. . .. .. .. . .. . .. .. . .. . .. .. . 59 

features of ...................................... 66-67.73 

heights of.......................................... 67 

location of......................................... 66 

profiles of, west of N a v1ure Peaks. . . . . . . . . . . . . . . . . . 75 

rocksof ............. _............................... 60 

topographJ' of...................................... 73 

:Methow peneplain, altitude of ........................ 87, 90 

Methow plain, altitude of .......................... 87,89-90 

probable origin of ................................. 70-71 

residuals of, distribution and character of ......... 72-75 

rocksof ................................... ,........ 71 

topography of ...... , ............................... 7!-72 

Methow quadrangle, southern half of, physiographic 

map showing .. .. .. . .. .. . .. . .. . . .. . .. .. . .. .. .. . 76 

Methow River, course, elevation, and grade of........ 87 

glacial deposits along.............................. 87 

\Iethow stage, age of .............. · .................... 69,70 

characteristic feature of . . .. .. .. .. .. . .. .. . .. .. .. . .. 70 

conditions of development of. ..................... 70-75 

downwarp during ................................. 86-87 

topographic type of................................. 68 

upwarp during ....................... .' ............ 88-89 

Methow Valley, glacial deposits ilL................... 87 

trend ol. .. .. . . .. .. . . . .. .. .. .. .. . .. . . . .. . .. . .. .. . .. . 86-87 

Miocene rocks, occurrence and character of ........... 16-19 

Moses Creek, topography at head of. ........ · .......... 51-52 

Mount. (See next word of entry.) 

Mount Stuart quadrangle, area, locution, and features 

of.............................................. 9 

dissection in .. . .. .. .. .. . . .. .. . . . .. . . .. . .. .. .. . . .. .. 31 

geologic mtlp of portion of...... . .. .. . .. . .. . . .. .. . 14 

geologic structure iii. ............................... 19-20 

Naches Rinr, character and history of................ 33 

Ellensburg formation along . . . . . . . . . . . . . . . . . . . . . . . 18 

Naches Val1ey, lava streams along.................... 18 

Navarre Coulee, features of ......................... 56,57,61 

history of .. : .................................. -..... 57 

view of, plate showing .. .. . .. .. . .. .. .. . .. .. .. . .. .. 56 

Navarre Creek, diversion of, by deformation.......... 61 

.Navarre Peaks, age of ................................. 73-74 

height of .. .. .. . .. .. .. .. .. .. .. .. . .. ... .. .. ..... .. .. 67 

rei a tions and origin of . .. . .. .. .. .. .. .. .. .. .. . .. . .. . 67 

view of, plate showing............................ 66 

Navarre stream, tributaries of......................... 61 

Oval Peak, height of .. . .. .. .. ... .. .. .. .. .. .. . .. .. . .. .. 75 

Peridotite, occurrence of .............................. 14-15 
IN:DEX. 101 

Page. 

Peshastin formation, age and character of............ 14 

Pleistocene deposits, occurrence and character of . . . . 19 

Pleistocene lavas, occurrence of....................... 18 

Powell, .1. W., references to ........................... 34,35 

Prince Creek, topogmphy of area near................ 83 

Red Slide, Chelan Butte, topography near............ 59 

Rhyolite-porphyry, occurrence of ..................... 60,65 

Rhyolitic rock, occurrence and age of. ................ 18-19 

Ribbon Blu!Y, Columbia River, topographic features . 

ncnr ··············--······--·-····--·-····-···· 49,50 

Ribbon :Mesa, altitude of.............................. 90 

height of .. .... . .. .. .. .. . .. . .. .. .. . .. .. .. .... . . .. .. . 73 

River terraces, occurrence of. ..................... _ ... _.. 51 

Rivers, history of. ..................................... 32-34 

Roslyn formation, coal seam in........................ 16 

occurrence and character of .. . .. .. .. . . .. .. .. . .. .. 16 

Russell, I. C., acknowledgmentsto.................... 47 

cited on Cascade Mountains .................... 11, 29,48 

cited on Columbia River lava ............... 10,11,12,13 

cited on Columbia River tributaries .. . ........... 53 

cited on geology of central Washington........... 10 

cited on Wenatchee gla<jcr...... .... .............. 54 

cited on Wenatchee River Canyon ................. 53-54 

references to . . .. .. . . .. .. . . .. .. .. .. .. .. .. .. .. . 68, 71, 75, 81 

Russell River, course of................................ 63 

diversion of ....................................... ; 62-63 

valley of, recognition of .. .. .. .. .. . .. .. .. .. .. .. .. .. 62 

Safety Harbor Creek, features of canyon above ........ 59-60 

rocks near head of................................. 60 

Salisbury, R. D., aid rendered by...................... 49 

Sawtooth Range, location of........................... 66 

Serpentine, occurrence and character of .............. 14-15 

ore veins in .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . .. .. .. . .. 15 

Smith, George Otis, acknowledgements to ........... : 47 

aid rendered by.. .. .. .. .. .. . .. . . .. .. . .. .. .. .. .. .. .. •18-49 

references to ........................ 64,68-72,79,86,91-92 

Snake River, gorge carved by .. .. .. .. .. .. .... . .. .. .. .. 11 

Snoqualmie quadrangle, glacial erosion in............ 36 

location of .. .. . .. .. .. .. . .. .. .. .. . .. .. .. . .. .. . .. .. .. 34 

map of ............................................ . 

physiography of ................................... . 

uplift in, axes of ................................. .. 

Snoqualmie River, diversion and former course of~ .. _ 

Spurr, J. E., cited on deformation ........ _ ........... .. 

Star Peak, height of. .................................. . 

Stehekin-Chelan Canyon, character and history of .. . 

Stehekin-Chelan River, source and course of ........ . 

Stehekin stage; age of ........... ' ................... .. 

characteristics of ................................. . 

Stormy Mountain, height of. ........................ .. 

topography of ..................................... . 

view of, plate showing .......................... .. 

Streams of the region, antecedent-character of ....... . 

Stress in the Cascade Range, direction of ............ . 

Structure, geologic, features of ...................... .. 

Strnmmel Canyon, topography near ..... : ............ . 

Stwut, Mount, geologic structure of. .......... : ...... . 

location and height of ........................... .. 

rock forming, character of.· ..................... .. 

Swank Basin, geld veins in .......................... .. 

Swank drainage basin, auriferous gravels in ......... . 

Swank formlltion, gold veins in, occurrence and character of ....................................... . 

36 

34-38 

37 

17 

94,95 

75 

60-61 

58,63 

70 

69,70 

62,89 

65 

66 

10 

92-95 

19-21 

66 

20 

22 

15 

15 

19 

15 

Page. 

Sympathetic and unsympathetic relations of topographic features, discussion of................. 71 

Tttneum Creek Valley, pre basalt surface of . . . . . . . . . . . 28 

Tca[laway basalt, occurrence and ehttracter of. ....... 15-16 

Tmnaway River, lavas on middle fork of ............. 18-19 

Terraces, occurrence of... .. . .. . .. .. . .. .. .. .. .. .. .. .. .. 51 

Tertiary period, deformation during .................. 91-92 

events of. .......................................... 11-12 

Tertiary rocks, reduction of .. .. .. .. .. . .. . .. .. .. .. .. .. . 28 

Tieton Basin, lava strcttms in.......................... 18 

Tieton Canyon, lavas in .. .. .. .. . .. . . . .. .. . .. .. .. .. .. .. 18 

Topographic features, sympathetic and unsympathetic relations of . .. .. . .. .. . .. . .. . .. .. . .. .. .. . 71 

Twenty-five Mile Creek, topography of urea ncar..... 83 

Twisp slope, line of rlemarcation between Entiat 

slope and .................................. ·.... 76 

Twisp stage, age of .................................... 69,70 

characteristic features of .....•................. 68-69,80 

topograpi1ic forms of, development of. ............ 80-81 

Tyee Mountain, height of ............................. 62,77 

Van Rise, C. R., cited on deiormation................. 94 

cited on rock flowage . .. . .. .. .. .. .. .. .. . .. . . .. .. .. 94 

Volcanic outbursts, lacustral sedimentation succeeding........................................ 11 

Volcanic rocks, occurrence of......................... 50 

Washington, central; map of.......................... 10 

topographic provinces of ....... c.................. 9 

Waterville downwarp, description of .. . .. .. .. .. ... . .. 90 

Waterville Plateau, location and features of ....... 51-53,72 

Wenas basalt, occurrences of.......................... 17 

Wenas Creek, history of ............................... 33-34 

Wenas Valley, geologic and topographic relations of.. 33 

Wenatchee, topographic features ncar................ 49 

Wenatchee-Chelan district, Cascade Range, map of . . 48 

rlrainage of .. .. .. . . . .. .. .. . . .. .. . . .. .. . .. .. .. . .. . .. 53 

physiographic profiles in, plate showing . . . . . . . . . . 78 

synthetic discussion of. ............................ 68-70 

Wenatchee downwarp and upwttrp, description of.... 91. 

Wenatchee Mountains, topography of................. 22 

uplift of. ......................................... 29-30, 91 

Wenatchee River, course of ................. :......... 53 

history of . .. .. .. .. .. . .. .. .. .. . . .. .. .. .. .. .. . .. . .. .. 53-54 

Wenatchee Valley, physiography of. .................. ·53-55 

White Bluffs, Columbia River, Ellensburg formation 

at............................................... 1s 

Willis, Bailey, acknowledgements to.................. 10 

references to ..................... :.. .. .. .. . .. .. . 28, 30, 31 

Yakima basalt, age, character, and thickness of ...... 16-17 

Yakima basalt and Ellensburg sandstone, contact of, 

figure showing................................. 27 

Yakima Canyon, basttlt in............................. 17 

map of, with geologic section .. .. .. .. .. .. . .. .. .. . . 32 

view of, at Beaver· Bend, plate showing........... 12 

Yakima region, landslides itt.......................... 23 

physiography of .. . .. .. .. .. .. . .. .. .. .. .. .. .. . .. . . .. 23 

uplift in, rate of .. .. .. .. .. .. .. .. .. .. . .. .. .. .. .. .. .. 86 

Yakima River, area druined by....................... 9 

character of ........................................ 38-39 

character and history of. .. .. . .. .. .. .. .. .. . .. .. .. . . 32 

region traversed by, features of .. .. . .. .. .. .. .. .. .. 9 

tributaries to, position of.......................... 33 

volcanic rocks along .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 17 

Yakima Valley, gravels in .. .. .... . .. .. .. .. . .. .... .. .. 19 

0 

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B 87. Synopsis of American fossil Brachiopoda, including bibliography and synonymy, by Charles Schuchert. 1897. 

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B 93. Some insects of special interest from Florissant, Colo., and other points in the Tertiaries of Colorado and Utah, by 

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Communications should be addressed to 

THE DIRECTOR, 

UNITED STATES GEOLOGICAL SURVEY, 

w· ASHINGTON, D. C. 

0C'l'OBE R, 1903. 
LIBRARY CATALOGUE SLIPS. 

[Mount each slip upon a separate card, placing the subject at the top of the 

second slip. The name of the series should not be repeated on the series· 

card, but the additional numbers should be added, as received, to the first 

entry.] 

Smith, George Otis . 

. : . Contributions to the geology of Washington: 

Geology and physiograpb,y of central Washington, by 

George Otis Smith; Physiogr~phy and deformation of 

the Wenatchee-Chelan district, Cascade Range, by 

Bailey Willis. Washington, Gov't print. off., 1903. 

101, IIIp. 20pl. (incl. maps), 3'fig. 29tx23'm. (U.S. Geological survey. Professional paper no. 19.) 

"Literature" : p. 10-13. 

Subject series 0, Systematic geology and paleontology, 64. 

Smith, George Oti's . 

. . . Contributions to the geology of Washington: 

Geology and physiography of central Washington, by 

George Otis Smith; Physiography and deformation of tl 

;Eo the Wenatchee-Chelan district, Cascade Range, by = "-' Bailey Willis. Washington, Gov't print. off., 1903. 

101, III p. 20 pl. (incl. maps), 3 fig. 29~ x 23'"'. (U. S. Geological survey. Professional paper no: 19.) 

"Literature": p. 10-13. 

Subject series 0, Systematic geology and paleontology, 64. 

u.s. Geological survey. 

Professional papers. 

~ no.· 19. Smith, G. 0. Contributions to the geology of 

Washington ... by G. 0. Smith and Bailey 

.Willis. 1903. 

.. 

J) 

U.S. Dept. of the Interior. 

see also 

U. S. Geological survey. 

14493-No. 19-03-8 III