GEOLOGICAL SURVEY Bl:JU.ETIN 

\. 

BALANCED ROCK, guarding The 

Windows section of Arches National 

Park. Rock is Slick Rock Member of 

Entrada Sandstone resting upon crinkly bedded Dewey Bridge Member of 

the Entrada . White rock in foreground 

is Navajo Sandstone. La Sal Mounta ins on right skyline. (Frontispiece) 

By S. W. lohman 

Graphics by 

John R Stacy 

GEOLOGICAL SURVEY BULLETIN 1393 
UNITED STATES DEPARTMENT OF THE INTERIOR 

ROGERS C. B. MORTON, Secretary 

GEOLOGICAL SURVEY 

V. E. McKelvey, Director 

U.S. GOVERNMENT PRINTING OFFICE: 1975 

Library of Congress Cataloging in Publication Data 

Lohman, Stanley William, 1907-

The geologic story of Arches National Park. 

(Geological Survey Bulletin 1393) 

Bibliography: p. 

Includes index. 

Supt. of Docs. no.: I 19.3:1393 

1. Geology-Utah-Arches National Park-Guide-books. 2. Arches National Park, 

Utah-Guide-books. 

I. Title. II. Series: United States Geological Survey 

Bulletin 139 3. 

QE75.B9 No. 1393 [ QE1 70.A 7) 557.3'08s [ 557.92'58) 

74-23324 

For sale by the Superintendent of Documents, U. S. Government Printing Office 

Washington, D. C. 20402 

Stock Number 024-001-02598-1 
Beginning of a monument ~ ~~~-~- . 

Graduation to a park ~~ 

Early history~. ~ 

Prehistoric people 

Late arrivals~~ 

Geographic setting ~ 

Deposition of the rock materials 

Bending and breaking of the rocks~ 

Uplift and erosion of the PlateaU~~~~ 

Origin and development of the arches 

Examples of arches. ~ 

How to see the park~ 

A trip through the park ~~ 

Colorado River canyon. 

Headquarters area~. . . 

Courthouse Towers area~ 

The Windows section~. 

Delicate Arch area ~~ 

Fiery Furnace ~ 

Salt Valley and Klondike Bluffs 

Devils Garden .. 

Summary of geologic historY~~ 

Additional reading 

Acknowledgments~~-~ 

Selected references~. 

Index~~~~~~~~~ 

Page 

1 

5 

9 

9 

12 

18 

20 

24 

33 

37 

46 

50 

52 

52 

57 

63 

68 

74 

79 

82 

83 

98 

104 

105 

105 

109 

VII 
Frontispiece. Balanced Rock. 

1. Arches National Park. .............. . 

2. Rock art in Arches National Park.. 

3. Wolfe's Bar-DX Ranch .. 

4. Rock column of Arches National Park. .. 

5. 

6. 

7. 

8. 

9. 

10. 

11. 

12. 

13. 

14. 

15. 

16. 

17. 

Common types of rock folds. . ................. . 

Common types of rock faults.......... .. . .................... . 

Paradox basin... . ..................... . 

Geologic section across northwest end of Arches National 

Park ................ ····-·······--·············-···--····················-············· 

Index map of northwestern part of Arches National Park 

Gravity anomalies over Salt Valley... . ................... . 

Tilted block of rocks in Cache Valley graben .................... . 

Jointed northeast flank of Salt Valley anticline ... . 

Index map........ ... . .............. . ............ . 

Tunnel Arch ........................................... . 

"Baby Arch" ................... . 

Broken Arch... . . 

Double Arch .............. . 

18. Pothole Arch .............. . 

19. Glen Canyon Group............. ........ ..... . ........................... . 

20. Navajo Sandstone cliffs...................... . ............................. . 

21. Mouth of Salt Wash.. . ............................................... . 

22. Southeast end of faulted Cache Valley anticline .............. . 

23. Faulted Seven Mile-Moab Valley anticline .. . 

24. Three Penguins ......... ... ........................... . ............ . 

25. Moab Valley...................... . ................................... . 

26. Faulted wall of Entrada Sandstone ................................... . 

27. Park A venue....................... . ................................. . 

28. Balanced rocks on south wall of Park Avenue ................... . 

29. Courthouse Towers .. . ............................................. . 

30. The Three Gossips ........................................................ . 

31. Sheep Rock... . .............................................. . 

32. Petrified sand dunes........ . ......................................... . 

33. "Hoodoos and goblins"-. . . . . ... ... . ... . . . .. . . . . . . .................... . 

34. Eye of The Whale....................... . ................... . 

35. Intricate crossbeds in Navajo Sandstone ............................. . 

36. Cove Arch and Cove of Caves .............................................. . 

37. North Window.................. . .................................... . 

38. Looking southwestward through North Window .............. . 

39. South Window.................. . ...................................... . 

40. Turret Arch ............... . 

41. Parade of Elephants 

VIII 

Page 

6 

11 

14 

21 

25 

26 

27 

28 

28 

31 

34 

36 

38 

43 

44 

45 

47 

48 

53 

54 

55 

56 

58 

59 

60 

61 

62 

64 

65 

66 

66 

67 

68 

69 

70 

71 

72 

73 

74 

75 

76 
Page 

42. Suspension foot bridge across Salt Wash------------·------·-------- 78 

43. Delicate Arch ____________ __________ ___________________ ______ ------------------------- 78 

44. Fiery Furnace_________ ____ ____________ ____________ ________ ____________ __ __ ___ _____ _____ 80 

45. Trail to Sand Dune Arch________________________________ __ _______________ __ ___ 81 

46. Sand Dune Arch ___ ____________ __ -- --- ·-------------------- ----- ------------------ 82 

47. Tower Arch·-----------------·---------------------·---------------------··-------·------- 84 

48. Skyline Arch __ ------------------------------------------------- -----------------··· 85 

49. Campground in Devils Garden·---····-·--·-----·------·-··-·······-··- 86 

50. View north from campground _______ _________ ___ _ ·--·-················-- 87 

51. Southeastern part of Devils Garden traiL..................... 88 

52. Pine Tree Arch _______ ___________ ---------------··· ----------·- ---·-···--·---- ·- - 89 

53. Landscape Arch _______________________ -------··------·- ---------------·---··---·-·- 91 

54. Navajo Arch _________ ______________ --- ·------------- ---------·--- _ 92 

55. Partition Arch __________ _________________________________ ·------- _ -···---- ----·---- 93 

56. Double 0 Arch __________________ --·- ___ ---------------------------------- _ 93 

57. Dark AngeL__________________________ __ ____________ __________ _____ ____ ____________ _____ 94 

58. "Indian-Head Arch" ---------·-------------·--·-·-·--·----·----·-·--··------ --- --· 95 

59. Geologic time spiraL ______ ________________ ____ ···-·--·--- -···--···-·--· ··- --- ··- 96 

IX 

AccORDING TO former Superintendent Bates Wilson (1956), Prof. Lawrence M. Gould, of the University of 

Michigan, was the first to recognize the geologic and scenic 

values of the Arches area in eastern Utah and to urge its 

creation as a national monument. Mrs. Faun McConkie 

Tanner1 told me that Professor Gould, who had done a 

thesis problem in the nearby La Sal Mountains, was first 

taken through the area by Marv Turnbow, third owner of 

Wolfe cabin. (Seep. 12.) When Professor Gould went into 

ecstasy over the beautiful scenery, Turnbow replied, "I 

didn't know there was anything unusual about it." 

Dr. J. W. Williams, generally regarded as father of the 

monument, and L. L. (Bish) Taylor, of the Moab TimesIndependent, were the local leaders in following up on 

Gould's suggestion and, with the help of the Moab Lions 

Club, their efforts finally succeeded on April 12, 1929, when 

President Herbert Hoover proclaimed Arches National 

'Mrs. T a nner, of Phoenix, Ariz., is the a uthor of a n earlier history of Moab 

( her home town ) . She has completed a revision entitled, "The F a r CountryA R egiona l History of Moa b a nd L a Sa l, Uta h," which will be serialized in 

the Moab Times-Independent, a fte r which it will be published . 

1 
Monument, then comprising only 7 square miles. 2 It was 

enlarged to about 53 square miles by President Franklin 

D. Roosevelt's Proclamation of November 25, 1938, andremained at nearly that size, with some boundary adjustments on July 22, 1960, until it was enlarged to about 130 

square miles by President Lyndon B. Johnson's Proclamation of January 20, 1969. 

According to Breed (1947), Harry Goulding, of Monument Valley, in a specially equipped car, traversed the 

rugged sand and rocks of the Arches region in the fall of 

1936 and, thus, became the first person to drive a car into 

The Windows section of Arches National Monument. Soon 

after, a bulldozer followed Harry's tracks and made a passable trail. 

When my family and I visited the monument in 1946, 

the entrance was about 12 miles northwest of Moab on 

U.S. Highway 163 (then U.S. 160), where Goulding's old 

tire tracks led eastward past a small sign reading "Arches 

National Monument 8 miles." This primitive road crossed 

the sandy, normally dry Courthouse Wash and ended in 

what is now called The Windows section. At that time 

there was no water or ranger station, nor were there any 

picnic tables or other improvements within the monument 

proper, and the custodian was housed in an old barracks 

of the Civilian Conservation Corps near what is now the 

entrance, 5 miles northwest of Moab. 

Former Custodian Russell L. Mahan reported (oral 

commun., May 1973) that soon after our initial visit in 1946 

a 500-gallon tank was installed near Double Arch in The 

Windows section and connected to a drinking fountain and 

that two picnic tables and a pit toilet were added. At that 

time the only access to Salt Valley and what is now called 

Devils Garden was a primitive dirt road which, according 

to Breed (1947, p. 175), left old U.S. Highway 160 (now 

U.S. 163) 24 miles northwest of Moab, went 22 miles east, 

'For the benefit of visitors from countries in which the metric system is 

used, the following conversion factors may be helpful: 1 inch = 2.54 centimeters, 1 foot= 0.305 meter, 1 mile = 1.609 kilometers, 1 U.S. gallon= 0.00379 

cubic meter. 

2 
then followed Salt Valley Wash down to Wolfe cabin 

(fig. 1). 

According to Abbey ( 1971) , who served as a seasonal 

ranger beginning about 1958, a sign had by then been 

erected at the crossing of Courthouse Wash which read: 

WARNING: QUICKSAND 

DO NOT CROSS WASH 

WHEN WATER IS RUNNING 

The ranger station, his home for 6 months of the year, was 

what Abbey described as "a little tin housetrailer." Nearby 

was an information display under a "lean-to shelter." He 

had propane fuel for heat, cooking, and refrigeration, and a 

small gasoline-engine-driven generator for lights at night. 

His water came from the 500-gallon tank, which was filled 

at intervals from a tank truck. At that time there were 

three small dry campgrounds, each with tables, fireplaces, 

garbage cans, and pit toilets. By that time an extension of 

the dirt road led northward to Devils Garden, and some 

trails had been built and marked. 

Bates Wilson became Custodian of the monument in 

1949 and later became Superintendent not only of Arches 

but also of the nearby new Canyonlands National Park 

(Lohman, 1974) and the more distant Natural Bridges 

National Monument. In the fall of 1969, Bates told me of 

some of his early experiences in the undeveloped monument, including the evening when 22 cars were marooned 

on the wrong (northeast) side of Courthouse Wash after 

a flash flood. Bates and his "lone" ranger brought ropes, 

coffee, and what food they could obtain in town after closing time, threw a line across the swollen stream, had a 

tourist pull a rope across, then took turns wading the 

stream with one hand on the rope and the other balancing 

supplies on his shoulder. After a fire had been built and hot 

coffee and food passed around, the spirits of the stranded 

group rose considerably, except for one irate woman 

from the East, who refused to budge from her car. Bates 

and his helper finally got the last car out about 1 a.m.; 

after the flood had subsided, and Mrs. Wilson then supplied lodging and more food and coffee for those who 

needed it. 

3 
During and for sometime after World War II and the 

Korean War, lack of maintenance funds and personnel had 

prevented improvement of the facilities in many of our national parks and monuments, particularly in undeveloped 

ones like Arches. The day was saved through the wisdom 

and foresight of former Park Service Director Conrad L. 

Wirth, who saw the need and desirability of putting the 

whole "want" list into one attractive, marketable package. 

In the words of Everhart (1972, p. 36): 

Selection of a name is of course recognized as the most important decision in any large-scale enterprise, and here Wirth struck 

pure gold. In 1966 the Park Service would be celebrating its 

fiftieth anniversary. What a God-given target to shoot for! Why 

not produce a ten-year program, which would begin in 1956, aimed 

to bring every park up to standard by 1966 - and call it Mission 66? 

The ensuing well-documented and cost-estimated plan 

for Mission 66 was enthusiastically backed by President 

Dwight D. Eisenhower and approved and well supported 

by Congress to the tune of more than $1 billion during 

the 10-year period. For Arches, this included a new entrance, Park Headquarters, Visitor Center, a museum 

boasting a bust of founder Dr. Williams, and modern 

housing for park personnel, all 5 miles northwest of Moab. 

By 1958 (Pierson, 1960) a fine new paved road between 

Park Headquarters and Balanced Rock (frontispiece) was 

completed. These badly needed improvements were followed by the completion of the paved road all the way to 

Devils Garden, the building of the modern campground, 

picnic facilities, and amphitheater in the Devils Garden, 

and the construction of turnouts and marked trails. 

4 
ARCHES GRADUATED to a full-fledged national 

park when President Richard M. Nixon signed a Congressional Bill on November 16, 1971. The change in status 

was accompanied by boundary changes that reduced the 

area to about 114 square miles. The loss of most of Dry 

Mesa, just east of the present boundary (fig. 1), was 

offset in part by gains of new land northwest of Devils 

Garden. The present (1974) boundaries, roads, trails, and 

named features of the park are shown in figure 1. 

The park was virtually completed at graduation time, 

and so far this change in status has shown up mainly in 

new entrance signs, a new 1972 brochure and map, and a 

very informative "Guide to an Auto Tour of Arches National Park," keyed to numbered signs at parking spaces. 

About all that remain to be added are new wayside exhibits, some boundary fences, and spur roads and trails. 

ARCHES NATIONAL PARK (overleaf), showing location in Utah, [> 

boundaries, streams, highways and roads, trails, landforms, principal named features, and the city of Moab. The reader is referred 

to figure 7 and to road maps issued by the State or by oil 

companies for the locations of other nearby towns and features . 

Visitors also may obtain pamphlets, from the entrance station 

or from the National Park Service office in Moab, which contain 

up-to-date maps of the park and the latest available information 

on roads, trails, campsites, and picnic sites. (Fig. 1) 

5 
EXPLANATION 

Paved road 

Gravel or dirt road 

_____., Jeep trail 

------ Foot trail 

Park Boundary 
~ .. - '1 

. I 

I 

··j -. -, 

I 

u T A 

~( ~ ~ 8v11. 

, I 

r _,: ·,.~-:;:;;;~·~ ~~ 

l 

• ~~ 0 ~ 

If. E SA - • _..,-

----' 
Although Arches had officially become a park in November 1971, it was not formally dedicated until May 15, 1972. 

The ceremony began by having the Federal, State, and 

local dignitaries and other guests totaling 140 persons 

board the Canyon King, a 93-foot replica of a Mississippi 

River stemwheeler (Lansford, 1972; Lohman, 1974, fig. 

69), for its maiden voyage down the Colorado River. After 

about half an hour, the heavily laden boat became stuck 

on a sandbar, and after a 90-minute wait the passengers 

were rescued by jet boats. This delayed a luncheon at the 

Visitor Center put on by the Moab Lions Club. Following 

the luncheon, Park Superintendent Bates Wilson made a 

brief welcoming address, then introduced J. Leonard Volz, 

Director of the Midwest Region of the National Park Service, who served as master of ceremonies. Speakers included Utah Governor Calvin L. Rampton, Senator Frank 

E. Moss, a representative of Senator Wallace F. Bennett, 

Representatives Sherman P. Lloyd of Utah and Wayne 

Aspinall of Colorado, and Mitchell Melich, Solicitor General 

of the Department of Interior, representing Secretary 

Rogers C. B. Morton. After the speeches, a commemorative 

plaque, donated by the Canyonlands Natural History Association, was unveiled by Senator Moss and Mr. Melich. 

Most of the color photographs were taken by me on 

4- X 5-inch film in a tripod-mounted press camera, using 

lenses of several focal lengths, but a few were taken on 

35-mm film, using lenses of various focal lengths. I am 

grateful to several friends for the color photographs credited to them in the figure captions. The black and white 

photographs were kindly loaned from the Moab and 

Arches files of the National Park Service. The points from 

which most of the photographs were taken are shown in 

figure 13. 

... 

8 
Prehistoric People 

:JHE CANYON LANDS in and south of Arches were 

inhabited by cliff dwellers centuries before the first visits 

of the Spaniards and fur trappers. Projectile points and 

other artifacts found in the nearby La Sal and Abajo 

Mountains indicate occupation by aborigines during the 

period from about 3000-2000 B.c. to about A.D. 1 (Hunt, 

Alice, 1956). The Fremont people occupied the area around 

A.D. 850 or 900, and the Pueblo or Anasazi people from 

about A.D. 1075 to their departure in the late 12th century 

(Jennings, 1970). Most of the evidence for these early 

occupations has been found in and south of Canyonlands 

National Park (Lohman, 1974), but some traces of these 

and possibly earlier cultures have been found also within 

Arches National Park. 

Ross A. Maxwell (National Park Service, written 

commun., 1941) investigated two caves in the Entrada 

Sandstone in the upper reaches of Salt Wash that contain 

Anasazi ruins. He mentioned that perhaps a dozen or more 

other caves should be checked for evidence of former occupation and, also, that he found several ancient campsites 

littered with flint chips and broken tools. 

One cave Maxwell explored some 5 miles north of Wolfe 

Ranch and north of the park is about 300 feet long and 

100 to 150 feet deep. It contains the remains of one or 

more ruins of a structure he thought may have covered 

much of the floor. The remaining parts of walls now are 

only two to four tiers of stones in height, although originally they may have been more than one story high. 

9 
Maxwell explored a second cave on the east side of Salt 

Wash, about 2 miles north of Wolfe Ranch, which contains 

16 storage cists of adobe. 

The faces of many older sandstone cliffs or ledges are 

darkened by desert varnish- a natural pigment of iron 

and manganese oxides. The prehistoric inhabitants of the 

Plateau learned that effective and enduring designs, called 

petroglyphs, could be created simply by chiseling or pecking through the thin dark layer to reveal the buff or tan 

sandstone beneath. Most petroglyphs were created by the 

Anasazi, but those showing men mounted on horses were 

done by Ute tribesmen after the Spaniards brought in 

horses in the 1500's. The Fremont people and some earlier 

people painted figures on rock faces, called pictographs, 

and some of these had pecked outlines. 

The so-called "Moab panel" was described by Beckwith 

(1934, p. 177) as a petroglyph, but, as pointed out by 

Schaafsma (1971, p. 72, 73), it comprises figures having 

pecked outlines and painted bodies, which actually are 

combinations of petroglyphs and pictographs. This beautifully preserved group of paintings is shown in the upper 

photograph of figure 2. Mrs. Schaafsma goes on to say, 

concerning the "Moab panel": 

The long tapered body, the antenna like headdresses, and the 

staring eyes are characteristic features of Barrier Canyon style 

figures elsewhere * * *. Of special interest here are the large 

shields held by certain figures. A visit to this site indicated that 

the shields, although apparently of some antiquity, have been 

superimposed over some of the Barrier Canyon figures. Whether 

or not this was done by the Barrier Canyon style artists themselves or later comers to the site is impossible to tell. 

Although definite proof seems lacking, she suggested 

(written commun., Nov. 3, 1973) that the "'Barrier Canyon style'3 * * * is earlier than the work in the same 

region clearly attributable to the Fremont." Note the 

three bullet holes in and near the right-hand shield. A 

ledge above the panel that contained petroglyphs during 

"Barrier Creek flows through Horseshoe Canyon in the detached unit of 

Canyonlands National Park. The canyon walls are adorned by striking pictographs (Lohman, 1974, fig. 2). "Barrier Canyon style" is named after the 

pictographs found in Horseshoe Canyon. 

10 
ROCK ART IN ARCHES NATIONAL PARK. A (above), "Moab panel," 

on cliff of Wingate Sandstone above U.S. Highway 163 between 

Courthouse Wash and Colorado River, believed to be the work 

of "Barrier Canyon" style people. B (below), Petroglyphs on ledge 

of sandstone in Morrison Formation on east side of Salt Wash 

just north of Wolfe Ranch, believed to have been cut by Ute 

tribesmen. (Fig. 2) 
her earlier visit had fallen to the base of the cliff by the 

time my wife and I inspected the panel in September 1973. 

Mrs. Schaafsma believes the petroglyphs in the lower 

photograph of figure 2 to be the work of Ute tribesmen, 

not only because of the horses, but also because of the 

stiff-legged appearance of the mountain sheep. Note the 

bullet hole above the panel. 

Late Arrivals 

Later arrivals in and near Arches National Park included first Spanish explorers, then trappers, cattlemen, 

cattle rustlers and horse thieves, followed in the present 

century by oil drillers, uranium hunters, jeepsters, and 

tourists. Butch Cassidy, the Sundance Kid, and other 

members of The Wild Bunch are known to have frequented 

parts of what is now Canyonlands National Park (Baker, 

Pearl, 1971) , but it is not certain whether or not any of 

them traversed what is now Arches National Park. 

The first settler in what is now Arches National Park 

was a Civil War veteran named John Wesley Wolfe, who 

was discharged from the Union Army about 3 weeks 

before the Battle of Bull Run because he suffered from 

varicose veins. In 1888 his doctor told him he had to leave 

Ohio for a dryer climate or he would not live 6 months, so 

he took his son Fred west and settled on a tract of 150 

acres along the west bank of Salt Wash, where his "Wolfe 

cabin" still stands (figs. 1, 3). From family letters and 

newspaper clippings compiled by Mrs. Maxine Newell and 

other members of the National Park Service (Maxine 

Newell, written commun., 1971), we learn what life in the 

area was like: · 

We have started a cattle spread on a desert homestead. We call 

it the Bar-DX [DX] Ranch. Fred and I live in a little log 

house on the bank of a creek that is sometimes dry, sometimes 

flooded from bank to bank with roaring muddy water. We are 

surrounded with rocks- g}gantic red rock formations, massive 

arches and weird figures, the like of which youve [sic] never 

seen. The desert is a hostile, demanding country, hot in summer, 

cold in winter. The Bar-DX Ranch is a day's ride from the nearest store, out of the range of schools. 

12 
Although John Wolfe had promised his wife and his 

other children that he would return home the first fall 

that his cattle sales netted enough money, he and Fred 

stayed on and on, and his wife refused to go west and 

join her husband and son. Eighteen years later he sent 

money from his pension check to his daughter, Mrs. Flora 

Stanley, his son-in-law, Ed Stanley, and his two grandchildren, Esther and Ferol, to join him and Fred at the 

ranch. Their train was met at Thompson Springs (now 

Thompson), Utah (fig. 7), by John Wolfe for the 30-mile 

ride to the ranch by horse and wagon. Sight of the tiny 

log cabin with only a dirt floor brought tears to his daughter's eyes, but her spirits rose considerably after John 

Wolfe promised to build a new log cabin with a wooden 

floor. But the children were enchanted with this strange 

country, with the building of the new cabin, and, especially, 

with getting to go rabbit hunting with Grandpa Wolfe. 

The Stanleys stayed at the ranch until Esther was 10, 

then moved to Moab to await the arrival of their third 

child, Volna. 

In 1910 John Wolfe sold the Bar-DX Ranch, and the 

entire family moved to Kansas. John Wolfe later moved 

back to Ohio, and died at Etna, Licking County, on 

October 22, 1913, at the age of 84, 25 years after his doctor 

had warned him to move to a dryer climate or face an 

early death. 

Wolfe had sold his spread to Tommy Larson, who later 

sold it to J. Marv Turnbow and his partners, Lester Walker 

and Stib Beeson. The old log cabin gradually came to 

be known as the "Turnbow cabin," and this name appeared 

on early maps of the area by the U.S. Geological Survey 

and on early pamphlets by the National Park Service, 

partly because Marv Turnbow served as a camphand in 

1927 assisting in the first detailed geologic mapping of the 

area (Dane, 1935, p. 4). In 1947 the ranch was sold to 

Emmett Elizondo, who later sold it to the Government 

for inclusion in what was then the monument. 

From information supplied by Wolfe's granddaughter, 

Mrs. Esther Stanley Rison, and his great-granddaughter, 

Mrs. Hazel Wolfe Hastier, who visited the cabin in July 

13 
WOLFE'S BAR-DX RANCH, on west bank of Salt Wash at start of 

trail to Delicate Arch. Left to right: Corral, wagon, "new" cabin, 

and root cellar. "Old" cabin, which formerly was to right of photograph, was washed away by a flood in 1906. (Fig. 3) 

1970, the original name Wolfe cabin, or Wolfe Ranch, has 

been restored, and appears on the newer maps and pamphlets. (See fig. 1.) What remains of Wolfe's Bar-DX 

Ranch is shown in figure 3. 

Arches National Park is surrounded by active uranium 

and vanadium mines and by many test wells for oil, gas, 

and potash; it is underlain by extensive salt and potash 

deposits. Oil and gas are produced a few miles to the north 

and east, and potash is being produced about 12 miles to 

the south (Lohman, 1974). 

Uranium and vanadium have been mined on the Colorado Plateau since 1898 (Dane, 1935, p. 176) and in the 

Yellow Cat area (also called Thompson's area), just north 

of the park (fig. 1), since about 1911 (Stokes, 1952, p. 7). 

The deposits in the Yellow Cat area occur in the Salt 

Wash Sandstone Member of the Morrison Formation (fig. 

4). According to Pete Beroni (U.S. Atomic Energy Commission, oral commun., August 6, 1973), some ore is still 

being produced in the Yellow Cat area, and the production 

of vanadium ore will increase as soon as the uranium mill 

at Moab is converted to also handle vanadium ore. The 

14 
Corral and so-called Shinarump mines along the southwest 

side of Moab Canyon just north of Sevenmile Canyon (fig. 

1) are still actively producing uranium ore from the Moss 

Back Member of the Chinle Formation, according to 

Mr. Beroni. 

The occurrences of salt and potash in and near the park 

and the attempts to find oil and gas nearby are discussed 

in a recent report (Rite and Lohman, 1973), and the 

deposits beneath Moab, Salt, and Cache Valleys are discussed in later chapters. 

In 1955 and 1956 the Pacific Northwest Pipeline, known 

also as the "Scenic Inch," was constructed by the Pacific 

Northwest Pipeline Corp. to transmit natural gas from 

wells in the San Juan Basin of northwestern New Mexico 

for a total of 1,487 miles to the Pacific Northwest, with 

additional pickups from gas fields in northeastern Utah, 

northwestern Colorado, and southwestern Wyoming (Walters, 1956). This 26-inch pipeline follows the general route 

of U.S. Highway 163 from Cortez, Colo., past Moab to 

Sevenmile Canyon 10 miles northwest of Moab, where it 

turns abruptly to the northeast and crosses about the middle of Arches National Park. It crosses the park road and 

the flat area between the Fiery Furnace and the southeast 

end of Devils Garden, but the scars are so well healed that 

most visitors are unaware of its existence unless they 

happen to look southwestward across Salt Valley, where 

the filled excavation is still visible. The filled trench also 

appears in the lower middle of figure 23. 

Unlike Canyonlands National Park a few miles to the 

south, Arches was not on the route of the famous early-day 

river expeditions of John Wesley Powell or of most of 

those that followed; however, the southeastern boundary 

of the park is the Colorado River, formerly the Grand, 

which was traversed by the first leg of the ill-fated BrownStanton expedition (Dellenbaugh, 1902, p. 343-369; Lohman, 1974). 

The canyon of the Colorado River along the southeastem park boundary is deep and beautiful and is a favorite 

stretch of quiet water for boaters and floaters. Partly 

paved State Highway 128 on the east bank is a part of a 

15 
most scenic drive from Moab to Cisco - a small railroad 

town about 32 miles northeast of the eastern border of 

figure 1 (fig. 7). This road has been variously called the 

"Moab Mail Road," the "Cisco Cutoff," the "Dewey 

Road," or the "Dewey Bridge Road" after an old suspension bridge (fig. 7) across the Colorado River at the old 

townsite of Dewey about 12 miles south of Cisco. During 

the summer this deep colorful canyon may be viewed at 

night by artificial illumination. Each evening one-half hour 

after sundown, an SO-passenger jet boat leaves a dock north 

of the highway bridge, carries passengers several miles upstream, then floats slowly downstream followed by a truck 

on the highway carrying 40,000 watts of searchlights 

which play back and forth on the colorful red canyon 

walls, while the passengers listen to a taped discourse. The 

entire trip requires about 2 hours. 

The spectacular arches and red rocks of Arches and 

vicinity have been used to advantage in making color movies and color TV shows. Parts of the recent Walt Disney 

film "Run, Cougar, Run" were filmed beneath Delicate 

Arch (fig. 43) , in Professor Valley of the Colorado River 

just east of the park (fig. 7), and in other sections of the 

canyon country. 

Ever since military jet aircraft broke the sound barrier, 

there has been a growing number of protests from concerned citizens, organizations, and National Park Service 

officials concerning the dangers sonic booms have posed to 

Indian ruins and delicate erosional forms in our national 

parks and monuments, such as natural bridges, arches and 

windows, balanced rocks, and natural spires or towers. 

Many instances of damaged ruins, roads, erosional forms, 

and broken windows were reported. My wife and I can 

vouch for the destructive power of such booms, for in 

October 1969, while we were having breakfast at Squaw 

Flat Campground in The Needles section of Canyonlands 

National Park, a particularly severe blast from a low-flying 

jet not only violently rocked our jack-supported trailer 

but broke the windshield of our car. 

At Arches National Park, particular fear was felt for 

Landscape Arch (fig. 53), thought to be the longest nat16 
ural stone arch in the world, and many a special round 

trip from headquarters involving 47 road miles and 2 

trail miles was made to check on the condition of this arch 

after especially loud sonic booms were heard. Finally, in 

April 1972, following a rash of newspaper and magazine 

articles that spread across the nation, the Secretary of the 

Air Force put a virtual stop to this danger by ruling 

that, except in an emergency (Moab Times-Independent, 

April 12, 1972) : 

Supersonic flights must not only avoid passing over national 

parks, they also may not fly near them, according to the new 

regulation. For each 1,000 feet of altitude, the pilot must allow 

one-half mile between the flight path and the park boundary. The 

regulation also prohibits supersonic flights below 30,000 feet 

(over land) so the high speed planes must allow 15 miles between 

the nearest park boundary and the flight path. 

Let us hope that with the aid of this long-needed regulation and cooperation from visitors, the arches will remain 

intact for many more generations to see. 

17 
gEOLOGISTS have divided the United States into 

many provinces, each of which has distinctive geologic and 

topographic characteristics that set it apart from the 

others. One of the most intriguing and scenic of these is 

the Colorado Plateaus province, referred to in this report 

simply as the Colorado Plateau, or the Plateau (Hunt, C. 

B., 1956, fig. 1) . This province, which covers some 150,000 

square miles and is not all plateaus, as we shall see, extends from Rifle, Colo., at the northeast to a little beyond 

Flagstaff, Ariz., at the southwest, and from Cedar City, 

Utah, at the west nearly to Albuquerque, N. Mex., at the 

southeast. Arches National Park occupies part of the Canyon Lands Section, one of the six subdivisions of the 

Plateau. As the names imply, the Canyon Lands Section 

of the Plateau comprises a high plateau generally ranging 

in altitude from 5,000 to 7,000 feet, which has been intricately dissected by literally thousands of canyons. 

Arches National Park is drained entirely by the Colorado River, whose deep canyon borders the park on the 

southeast (fig. 1). Most of the park is drained by Salt 

Wash, which enters the Colorado River just southeast of 

The Windows section, but the southwestern part is drained 

by Courthouse Wash and Moab Canyon, whose flows 

join the Colorado just west of the bridge on which U.S. 

Highway 163 crosses the river. 

When viewed at a distance of 1 foot, the shaded relief 

map (fig. 1) shows the general shape of the land surface 

in and near Arches National Park to the same horizontal 

scale as it would appear to a person in a spacecraft flying 

at a height of 250,000 feet, or about 47.5 miles. This map 

18 
was prepared from part of the reverse side of a plasticrelief map4 at a scale of 1:250,000 by the U.S. Army Map 

Service of the Moab quadrangle, using a simple time- and 

money-saving method (Stacy, 1962). 

'Plastic-relief maps are no longer available from the U.S. Army Map Service but may be obtained from the T. N. Hubbard Scientific Co., Box 105, 

Northbrook, Ill. 60062. A topographic map at a scale of 1:250,000 of the 

Moab quadrangle and similar maps at a scale of 1:62,500 for the Thompson, 

Cisco, Moab, and Castle Valley quadrangles are available from the U.S. Geological Survey, Denver Distribution Section, Federal Center, Denver, Colo. 

80225, from the Canyonlands Natural History Association at Moab, and from 

privately owned shops where maps are sold. Most of the park is covered by the 

Thompson and Moab quadrangles. The southern part of the park is shown also 

on the Moab 4 NW, Moab 4 NE, and Mt. Wass 3 NW quadrangles at a scale 

of 1:24,000. A special topographic map of Arches National Park at a scale of 

1:50,000 is in preparation by the U.S. Geological Survey. These maps also 

may be obtained from the above-listed sources. 

19 
:JHE VIVID and varied colors of the bare rocks and 

the fantastic buttes, spires, columns, alcoves, caves, arches, 

and other erosional forms of Arches National Park result 

from a fortuitous combination of geologic and climatic 

circumstances and events unequalled in most other parts 

of the world. 

First among these events was the piling up, layer upon 

layer, of thousands of feet of sedimentary rocks under a 

wide variety of environments. Sedimentary rocks of the 

region are composed of clay, silt, sand, and gravel carried 

and deposited by moving water; silt and sand transported 

by wind; and some materials precipitated from water solutions, such as limestone (calcium carbonate), dolomite 

(calcium and magnesium carbonate), gypsum (calcium 

sulfate with some water), anhydrite (calcium sulfate 

alone), common salt (sodium chloride), potash minerals, 

such as potassium chloride, and a few other less common 

types. Some of the beds were laid down in shallow seas 

that once covered the area or in lagoons and estuaries 

near the sea. Other beds were deposited by streams in inland basins or plains, a few were deposited in lakes, and 

the constituents of deposits like the Navajo Sandstone, 

were carried in by the wind. The character and thickness 

ROCK COLUMN OF ARCHES NATIONAL PARK. Average thickness t> 

of units 250-1,000 feet is exaggerated two times; those less than 

250 feet, four times. 1 foot = 0.305 meter. (Fig. 4) 

20 
160 

250 Parmien Coder 

Formation 

llnnemell 

IJIIIIIIf' ..._.,,_ 

-ien ...... 300 

lmgularly bedded buff to led stndstone, led mvdltone, limatont, lftd conglo 

ate. lenlicular Sllldstone lftd contlo- IMoss lllck Member) locally at 

fled wood, reptile bones. Forms slopes. 

Thin-Hided b,_ shale, gray lftd b,_ stndstone, arkalle grit, lftd 

gto-. cro .. out on southMit side o1 Moeb Valley lftd In-" pi 

In Slit lftd Ceebe Valleys. For1111 slopes. 

Chocolate brown lftd led elftdy shale, maroon lftd pinkish-traY arkose 

lftd contlo-. "- part probebly equiVIIIftt in • to Rico 

F0f111atlon in - to eouth lftd eeet. Cro.- out in Moeb Cenyon - o1 Moeb flult. fOillll sloiiiJ. 

Grey -'ne fOIIilifwoua elftdy limatont, lilY lftd lfllllllh· gray llftdstone lftd elftdy shlle,llld led elftdy sllllt. Exposed in 

lldgllsoum- of Moeb fault in highway cut - of park tn· 

-· Slit, gy .. um, lftd tnhydritt, witb bltek lftd gray shale lftd lime· stone. few ex~ in Slit lftd Cecht Valleys. FOI'Jil$ siOPII. 

H,_Cmtk, 

Ani- Ri111r Valley, 

Colo • 

l'lredox Valley, Colo. 
of the exposed sedimentary rocks and the names and ages 

assigned to them by geologists are shown in the rock 

column (fig. 4) and in the cross section (fig. 8) . The history of their deposition is summarized on pages 98-102. 

Figure 4 was compiled mainly from generalized sections 

given by A. A. Baker (1933), Dane (1935), McKnight 

(1940), and Wright, Shawe, and Lohman (1962), and, in 

part, from Rite and Lohman (1973). 

Not exposed in the area but present far beneath the 

sedimentary cover and exposed in several places a few 

miles to the northeast are examples of the other two 

principal types of rocks- (1) igneous rocks, solidified 

from molten rock forced into or above preexisting rocks 

along cracks, joints, and faults, and (2) much older metamorphic rocks, formed from other preexisting rock types 

by great heat and pressure at extreme depths. Igneous 

rocks of Tertiary age (fig. 59) form the nearby La Sal 

Mountains. The particles comprising the sedimentary 

rocks in the area were derived by weathering and erosion 

of all three types of rocks in various source areas. 

Arches National Park and nearby Canyonlands National Park are both in the heart of the Canyon Lands 

Section of the Plateau; therefore, it is only reasonable to 

wonder why the differences in their general character seemingly outweigh their similarities. First, let us consider the 

similarities. Both parks are underlain by dominantly red 

sedimentary rocks, both parks feature unusual erosional 

forms of sandstone, and both contain beautiful natural 

arches, although the arches in Canyonlands are restricted 

almost entirely to the southeastern part of The Needles 

section and are in much older rocks than those in Arches. 

To be sure, differences in the rocks themselves play a 

part in the dissimilarity of the two parks, and these differences are of two types. First, there are lateral changes in 

the character of the strata, known to geologists as facies 

changes, brought about by differences in the environment, 

in the type of materials, and in the mode of deposition 

even within relatively short distances. Thus, during parts 

of the Permian Period while sand, later to be known as 

the Cedar Mesa and White Rim Sandstone Members of 

22 
the Cutler Formation, was being deposited in the southern 

part of Canyonlands, red mud, silt, and sand of the Cutler 

were laid down farther north in Canyonlands (Lohman, 

1974, fig. 9), and similar, though somewhat coarser, beds 

of the Cutler were laid down at Arches (fig. 4). Further 

comparisons of the rock columns in the two parks show 

that while limestones of the Rico Formation were being 

deposited in a shallow sea in the southern part of Canyonlands, additional red mud, silt, and sand of the Cutler 

were being laid down above sea level in areas to the northeast. The source of the coarser materials was the ancient 

Uncompahgre Highland, which stood above sea level from 

Late Pennsylvanian time to Late Triassic time (figs. 7, 

59). Although wider and longer, it occupied about the 

same position as the present Uncompahgre Plateau between Grand Junction and Gateway, Colo. Streams eroded 

the hard igneous and metamorphic rocks from this ancient 

landmass and dumped the material into basins to the 

northeast and southwest. The basin to the southwest, now 

called the Paradox basin (after Paradox Valley, Colo.), at 

intervals contained shallow seas and lagoons, which I will 

discuss later. 

Comparison of the rock columns for the two parks also 

reveals other differences. Both parks contain exposures of 

rocks as old as the Pennsylvanian Paradox Member of the 

Hermosa Formation. However, only in the Horseshoe Canyon Detached Unit of Canyonlands are rocks as young as 

the Jurassic Entrada Sandstone, whereas all the spectacular natural arches that make Arches famous were formed 

in the Entrada Sandstone, and Arches also contains several younger formations of Jurassic and Cretaceous age 

(fig. 4). 

A commonly asked question is "Why are most of the 

rocks so red, particularly those in which the arches were 

formed?" This can be answered with one word- iron, the 

same pigment used in rouge and in paint for barns and 

boxcars. Various oxides of iron, some including water, 

produce not only brick red but also pink, salmon, brown, 

buff, yellow, and even green or bluish green. This does not 

imply that the rocks could be considered as sources of 

23 
iron ore, for the merest trace, generally only 1 to 3 percent, 

is enough to produce even the darkest shades of red. The 

white or nearly white Navajo Sandstone and the Moab 

Member of the Entrada Sandstone contain little or no iron. 

As pointed out by Stokes (1970, p. 3), microscopic 

examination of the colored grains of quartz or other 

minerals shows the pigment to be merely a thin coating on 

and between white or colorless particles. Sand or silt 

weathered from such rocks soon loses its color by the 

scouring action of wind or water, so that most of the sand 

dunes and sand bars are white or nearly so. 

PERHAPS THE GREATEST geologic contrast between 

these two closely adjacent parks lies in their different geologic structure- the kind and amount of bending and 

breaking of the once nearly flat lying strata. Consolidated 

rocks, particularly brittle types, are subject to two types 

of fracturing by Earth forces. Joints are fractures along 

which no movement has taken place. Faults are fractures 

along which there has been displacement of the two sides 

relative to one another (fig. 6). As noted in the report on 

Canyonlands National Park (Lohman, 1974), the strata 

there, particularly along the valley of the Green River, are 

virtually flat lying or have only very gentle dips. Along the 

Colorado River above the confluence with the Green, however, the slightly dipping strata are interrupted by several 

gentle anticlinal and synclinal folds (fig. 5) and by at 

least one fault (fig. 6). The largest of these folds - the 

Cane Creek anticline, which crosses the Colorado River 

north of Canyonlands - has yielded oil in the past and is 

24 
COMMON TYPES OF ROCK FOLDS. Top, Anticline, or upfold; 

closed anticlines are called domes. Bottom, Syncline, or downfold; closed synclines are called basins. From Hansen (1969, p. 31, 

108). (Fig. 5) 

now yielding potash by solution mmmg of salt beds in 

the Paradox Member of the Hermosa Formation. 

In strong contrast to Canyonlands, Arches National 

Park contains three northwesterly trending major folds 

and is bordered on the southwest by a fourth. The largest 

and most important are the collapsed Salt Valley and 

Cache Valley anticlines, which separate the two most 

scenic groups of arches and other erosional forms - Eagle 

Park, Devils Garden, Fiery Furnace, and Delicate Arch 

on the northeast, and Klondike Bluffs, Herdina Park, and 

The Windows section on the southwest. Farther southwest is the Courthouse syncline, containing the attractive 

group of erosional forms called Courthouse Towers (fig. 

25 
COMMON TYPES OF FAULTS. Top, Normal, or gravity fault, resulting from tension in and lengthening of the Earth's crust. Bottom, reverse fault, resulting from compression in and shortening 

of the Earth's crust. Low-angle reverse faults generally are called 

overthrusts or overthrust faults. In both types, note amount of 

displacement and repetition of strata . Displacements may range 

from a few inches or feet to many thousands of feet. From Hansen 

(1969, p. 116). (Fig. 6) 

1). Finally, near the southwest edge of the park, is the 

Seven Mile-Moab Valley anticline (also known as the 

Moab-Spanish Valley anticline), whose southwest limb is 

cut off by the Moab fault (figs. 7, 23). The folds just 

named and the sharply contrasting geologic structures of 

the two parks are well shown on sheet 2 of the geologic 

map of the Moab quadrangle (Williams, 1964), and the 

geologic formations are shown in color on sheet 1. 

Arches National Park and most of nearby Canyonlands 

26 
N 

1 

j EXPLANATION 

D Area underlain 

by common salt 

D Area underlain by 

common salt and 

major potash deposits 

10 

Cortef 

-+-- Axis of anticline 

MilES 

20 

20 .. o KILOMETERS 

PARADOX BASIN, in southeastern Utah and southwestern Colorado, showing the extent of common salt and major potash deposits 

in the Paradox Member of the Hermosa Formation, and the salt 

anticlines. Adapted from Hite (1972, fig. 18). (Fig. 7) 

30 •o 

60 
"' "' IU 

oIU 

::!: 

0 

0 

0 

"' 

0 

0 

~ 

~ 

IU 

~ 

<( 

IU 

"' 

0 

0 

~ 

0 

0 

0 

"' I 

0 

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M 

I 

WEST 

A 

tii 

t:: 

COURTHOUSE SYNCLINE 

.4 MILES r-,...__.__~,.._,----'" -r 

6 KILOMETERS 

National Park lie within what geologists have termed the 

"Paradox basin," which contains a remarkable assemblage 

28 
EAST 

LT VALLEY ANTICLINE 

0 

I 

0 

Test well for 

oil and gas 

I 

2 

I 3 

I 4 MILES 

I I I I I 

5 6 KILOMETERS 

6 GEOLOGIC SECTION ACROSS NORTHWEST END OF ARCHES 

NATIONAL PARK, showing strata beneath Courthouse syncline and 

Salt Valley anticline. For line of section, see figure 9. Caprock 

consists of gypsum and shale, from which common salt has been 

leached by ground water, covered by alluvium. Heavy slanted lines 

near crest of anticline are faults. Adapted from Hite and Lohman 

(1973, fig. 13). (Fig. 8) 

<J INDEX MAP OF NORTHWESTERN PART OF ARCHES NATIONAL 

PARK, showing axes of Courthouse syncline and Salt Valley anticline, line of section A- A' in figure 8 and line of section B-B' in 

figure 10. Open circles along line of section are sites of test wells 

for oil, gas, or potash. Adapted from Hite and Lohman (1973, fig . 

12). (Fig. 9) 

of sediments called the Paradox Member of the Hermosa 

Formation. These deposits were laid down in shallow seas 

and lagoons during Middle Pennsylvanian time, roughly 

300 million years ago (fig. 59). As indicated in figure 4, 

the Paradox Member contains, in addition to shale and 

limestone, minerals deposited by the evaporation and concentration of sea water - common salt, gypsum, anhydrite, and potash salts. For this reason such deposits are 

29 

A' 

t:i 

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0 

0 

0 

.., 

0 

0 

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0 

0 

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0 

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0 

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collectively called evaporites. Figure 7 also shows that the 

northeastern part of the Paradox basin, which is the 

deepest part, contains a series of partly alined anticlines 

which have cores of salt and, hence, are called salt anticlines. As might be expected, roughly alined synclines 

intervene between the anticlines, but are not shown because of space limitations. According to Cater (1970, p. 

50): "The salt anticlines of Utah and Colorado are unique 

in North America both in structure and in mode of development." To this may be added that they also are 

relatively rare in the world. 

A section across the Salt Valley anticline and the Courthouse syncline in the northwestern part of the park is 

shown in figure 8, and the axes of these structures are 

shown in figure 9. 

Normally, a series of roughly parallel northwestwardtrending folds would result from shortening of a segment 

of the Earth's crust by compressive forces from the northeast and the southwest, but such does not seem to be 

the origin of these folds. The folds occur in a relatively 

narrow belt along the northeastern part of the Paradox 

basin, the deepest part, which was broken by a series of 

northwesterly trending normal faults (fig. 6) that cut the 

deep-lying Precambrian and older Paleozoic rocks (fig. 8) 

prior to the deposition of the salt-bearing Paradox Member of the Hermosa Formation. Movement along these 

faults continued intermittently during and after deposition of the Paradox, however, and resulted in the formation of a series of northwesterly trending ridges and 

troughs. Following Paradox time, normal sediments derived from a rising landmass to the northeast began to fill 

the basin. These sediments accumulated most rapidly and 

to greater thicknesses in the fault-derived troughs. Salt 

differs from normal sediments in two properties critical 

to the development of salt anticlines: first, salt is considerably lighter (fig. 10), and, second, salt under pressure 

will flow slowly by plastic deformation, much like ice in a 

glacier flows slowly downstream. Thus, salt in the troughs 

underlying the thicker and heavier masses of sediments 

was squeezed into the adjoining ridges, causing them to 

30 
8 8' + 10 

- 10 

/OBSERVED GRAVITY ANOMALY 

- 20 

JoL-----------------------------------------~ 

"' "' w ,__ 

~ ~ 

0 6 KILOMETERS 

GRAVITY ANOMALIES OVER SALT VALLEY, along line B-8' shown 

in figure 9, and relative densities and shapes of rock bodies beneath. Densities are in grams per cubic centimeter. Gravity values 

are in milligals, as shown. The standard acceleration of gravity is 

980.665 centimeters per second per second; 1 gal is equal to 1 

centimeter per second per second, and 1 milligal is one thousandth 

of a gal. Modified from Case and Joesting (1972, fig. 2). (Fig. 10) 

rise. Once started, this process tended to be self-perpetuating, as the flow of salt from beneath the thick masses 

of sediments in the troughs made room for the accumulation of still greater thicknesses of normal sediments. Consequently, the troughs receiving most of the sediments 

began to form downfolds, or synclines, and the ridges 

receiving little or no normal sediments began to form huge 

salt rolls that later were to become the cores of the salt 

anticlines when finally the ridges too were buried by sediments. Thus, the cross section (fig. 8) shows about 12,000 

feet of the Paradox Member beneath the crest of the Salt 

Valley anticline and only about 2,000 feet beneath the 

Courthouse syncline. Near the middle of these structures 

farther to the southeast, all the Paradox Member has been 

squeezed out from beneath the bordering synclines. 

The general shape of the Salt Valley anticline is shown 

also by cross-section B-B' (fig. 10), taken along the north31 
east-southwest line B-B' in figure 9, which is based upon 

so-called gravity anomalies over Salt Valley. The lighter 

Paradox Member, having an average density of 2.20, has a 

lower gravitational attraction than the heavier rocks on 

each side, which have an average density of 2.55. 

By this time you are doubtless wondering why prominent upfolds of the rocks, such as the Salt Valley anticline and associated Cache Valley anticline and the Seven 

Mile-Moab Valley anticline, now underlie relatively deep 

valleys bordered by prominent ridges. The formation of 

these valleys was not simple and involved many steps 

extending over a considerable amount of geologic time, as 

portrayed by Cater (1970, fig. 13; 1972, fig. 4). For a part 

of the story, let us reexamine the cross section (fig. 8); 

the rest of the story will be told in the section on "Uplift and Erosion." 

Figure 8 shows that the unnamed upper member of the 

Hermosa Formation and the overlying Cutler and Moenkopi Formations are thickest beneath the Courthouse 

syncline but wedge out against the flanks of the anticline. 

Although the Chinle Formation and younger rocks appear 

to extend across the fold, and may have extended across 

this part of the fold, in Colorado all rocks older than the 

Jurassic Morrison wedge out against the flanks of the 

salt anticlines (Cater, 1970, p. 35) and also in the widest 

part of the Salt Valley anticline southwest of the section 

in figure 8. The salt anticlines were uplifted in a series of 

pulses so that some formations either were not deposited 

over the rising structures or were removed by erosion before deposition of the next younger unit. By Morrison 

time the supply of salt beneath the synclines seems to 

have become used up; hence, the anticline stopped rising, 

and the Morrison and younger formations were deposited 

across the structures. Thus, in figure 4, the minimum 

thickness of all units older than the Morrison is given 

as zero. Figure 4 shows the marine Mancos Shale to be 

the youngest rock unit exposed in the park, but the Mesaverde Group of Late Cretaceous age and possibly the 

early Tertiary (fig. 59) Wasatch Formation may have 

been deposited and later removed by erosion. 

32 
nEXT AMONG the main events leading to the formation of landforms in the park was the raising and additional buckling and breaking of the Plateau by Earth 

forces partly during the Late Cretaceous but mainly during the early Tertiary. After uplift and deformation, the 

Plateau was vigorously attacked by various forces of 

erosion, and the rock materials pried loose or dissolved 

were eventually carted away to the Gulf of California by 

the ancestral Colorado River. Some idea of the enormous 

volume of rock thus removed is apparent when one looks 

down some 2,000 feet to the river from any of the high 

overlooks farther south, such as Dead Horse Point (Lohman, 1974, fig. 15). Not so apparent, however, is the fact 

that younger Mesozoic and Tertiary rocks more than 1 

mile thick once overlaid this high plateau but have been 

swept away by erosion. In all, the river has carried 

thousands of cubic miles of sediment to the sea and is 

still actively at work on this gigantic earth-moving project. In an earlier report (Lohman, 1965, p. 42) I estimated 

that the rate of removal may have been as great as about 

3 cubic miles each century. For a few years the bulk of 

the sediment was dumped into Lake Mead, but now Lake 

Powell is getting much of it. When these and other reservoirs ultimately become filled with sediment- for reservoirs and lakes are but temporary things - the Gulf of 

California will again become the burial ground. 

According to Cater (1970, p. 65-67), who made an intensive study of the salt anticlines, collapse of their crests 

seemingly occurred in two stages - the first stage following Late Cretaceous folding; the second following uplift 

33 
TIL TED BLOCK OF ROCKS IN CACHE VALLEY GRABEN, viewed to 

the east toward Cache Valley from point on gravelled side road to 

Wolfe's cabin, about half a mile east of paved road. Steep slope on 

left composed of Jurassic Morrison Formation, hogback on top 

formed by Dakota Sandstone of Late Cretaceous age, and gentle 

slopes to right composed of the Mancos Shale of Late Cretaceous 

age. (Fig. 11) 

of the Plateau later in the Tertiary. Solution and removal 

of salt by ground water played the leading role in the 

ultimate collapse. 

As shown by Dane (1935, pl. 1, p. 121-126), collapse 

of the Salt Valley and Cache Valley anticlines was accompanied by considerable faulting and jointing, particularly along their northeast sides; by the upward intrusion 

of two large areas of the Paradox Member of the Hermosa 

Formation, one just northwest of the park and one in the 

middle of Salt Valley south of the campground; and by 

two downdropped masses of rock known to geologists as 

grabens (pronounced grabans) - one just northwest of 

the park and one called the Cache Valley graben, which 

extends both east and west from Salt Wash. The Cache 

Valley graben has preserved from erosion the youngest 

rock formations in the park, as shown in figure 11. 

The remarkable jointing of the rocks on the northeast 

limb of the Salt Valley anticline is shown in figure 12. 

All the arches in this section of the park were eroded 

through thin fins of the Slick Rock Member of the En34 
trada Sandstone, and some, like Broken Arch, figure 16, 

are capped by the Moab Member. 

Differences in the composition, hardness, arrangement, 

and thickness of the rock layers determine their ability to 

withstand the forces of fracturing and erosion and, hence, 

whether they tend to form cliffs, ledges, fins, or slopes. 

Most of the cliff- or ledge-forming rocks are sandstones 

consisting of sand deposited by wind or water and later 

cemented together by silica (Si02), calcium carbonate 

(CaC03), or one of the iron oxides (such as FeD3), but 

some hard, resistant ledges are made of limestone (calcium 

carbonate). The rock column (fig. 4) shows in general 

how these rock formations are sculptured by erosion and 

how they protect underlying layers from more rapid erosion. The nearly vertical cliffs along the lower reaches of 

Salt and Courthouse Washes and the Colorado River 

canyon upstream from Moab consist of the well-cemented 

Wingate Sandstone protected above by the even harder 

sandstones of the Kayenta Formation. (See figs. 21, 22.) 

To borrow from an earlier report of mine (Lohman, 1965, 

p. 17), "Vertical cliffs and shafts of the Wingate Sandstone endure only where the top of the formation is capped 

by beds of the next younger rock unit- the Kayenta 

Formation. The Kayenta is much more resistant than the 

Wingate, so even a few feet of the Kayenta * * * protect 

the rock beneath." In some places, as shown in figures 19 

and 20, the overlying Navajo Sandstone makes up the 

topmost unit of the cliff. 

Last but far from least among the factors responsible 

for the grandeur of Arches National Park and the Plateau 

in general is the desert climate, which allows one to see 

JOINTED NORTHEAST FLANK OF SALT VALLEY ANTICLINE, viewed C> 

westward from an airplane. Light-colored wedge in middle background is Salt Valley bordered on extreme left by Klondike Bluffs. 

Dark-colored fins and pinnacles on left, of Slick Rock Member of 

the Entrada Sandstone, form Devils Garden. Sharp pinnacle above 

valley is the Dark Angel. (See fig. 57.) White bands of sandstone 

extending to foreground are composed of Moab Member of the 

Entrada. Note vegetation in the joints. Photograph by National Park 

Service. (Fig. 12) 

35 

virtually every foot of the vividly colored naked rocks, 

and which has made possible the creation and preservation 

of such a wide variety of fantastic sculptures. A wetter 

climate would have produced a far different, smoother 

landscape in which most of the rocks and land forms 

would have been hidden by vegetation. On the Plateau 

the vegetation grows mainly on the high mesas and the 

narrow flood plains bordering the rivers, but scanty vegetation also occurs on the gentle slopes or flats. 

The combination of layers of sediments of different composition, hardness and thickness, the bending and breaking 

of the rocks, and the desert climate, has produced steep 

slopes having many cliffs, ledges, and fins with generally 

sharp to angular edges, rather than the subdued rounded 

forms of more humid regions. 

AMONG THE QUESTIONS commonly asked by visitors are, "How do arches form?", "Why are some openings 

called windows, others arches?", "What is the difference, 

if any, between arches or windows and natural bridges, 

such as those at Natural Bridges National Monument?", 

and "How many arches are there in Arches National 

Park?" Before taking up the origin and development of 

arches, I shall attempt to explain the differences between 

the three types of natural rock openings named above and 

comment upon the number of arches. 

37 
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INDEX MAP, showing localities where 

most of the photographs were taken. 

Arrows point to distant views. Numbers refer to figure numbers. (Fig. 13) 
I believe most geologists and geographers are in general 

agreement with Cleland (1910, p. 314) that "a 'natural 

bridge' is a natural stone arch that spans a valley of 

erosion. A 'natural arch' is a similar structure which, however, does not span an erosion valley." According to this 

definition, Natural Bridges National Monument includes 

three true bridges, whereas all the larger rock openings in 

Arches National Park with which I am familiar are properly termed "arches," but some are called windows. If we 

were to distinguish between arches and windows, we might 

say that arches occur at or near the base of a rock wall, 

as do the doors of a house or building, whereas windows 

are found well above ground level. This distinction was 

not followed in naming the rock openings in the park, 

however; for example, Tunnel Arch (fig. 14) is considerably higher above the ground than North Window (figs. 

37, 38) or South Window (fig. 39). 

As to the number of arches in the park, I might begin 

by saying that there is no universal agreement as to how 

large a rock opening must be to qualify as an arch. The 

pamphlet formerly handed to visitors entering the park 

proclaimed that "Nearly 90 arches have been discovered, 

and others are probably hidden away in remote and rugged parts of the area," but the average visitor probably 

sees less than a third of this number. 

David May, Assistant Chief of Interpretation and Resource Management, Moab office of National Park Service 

(oral commun., Oct. 1973), believes that if only those in 

the park having a minimum dimension of 10 feet in any 

one direction were considered to be arches, the number 

would boil down to about 56 or 57. The most complete 

count of arches and other openings in all of southeastern 

Utah was made by Dale J. Stevens, Professor of Geography at Brigham Young University, during the period 

February through April 1973. He considered those with 

openings of 3 feet or larger and found more than 300 in 

southeastern Utah, of which 124 are in Arches National 

Park, although he stated that several areas of the park 

were not intensively searched because of time limitations 

(written commun., July and Sept. 1973). The 124 arches 

40 
and openings are distributed among the several named 

areas of the park, as follows: Courthouse Towers, 13; 

Herdina Park, 11; The Windows section, 25; Delicate Arch 

area, 3; Fiery Furnace, 19; Devils Garden, 25; upper Devils 

Garden (northwest of Devils Garden), 14; Eagle Park, 2; 

and Klondike Bluffs, 12. 

Professor Stevens generally used a range finder or a 

steel tape to measure the width and height of the openings and the width and thickness of the spans, but estimated a few of the dimensions. In the text descriptions of 

arches or captions of figures that follow, I am including 

all or part of these measurements, without further acknowledgment. 

All the arches in the park were formed in the Entrada 

Sandstone, mainly in the Slick Rock Member but partly 

in the Slick Rock and Dewey Bridge Members, and a few 

in the Slick Rock Member occur not far beneath the base 

of the overlying Moab Member. The sandstone of the 

three members is composed mainly of quartz sand cemented together by calcium carbonate (CaC03), which also 

forms the mineral calcite and the rock known as limestone, but the Dewey Bridge Member also contains beds 

of sandy mudstone. Limestone and calcite are soluble in 

acid, even in weak acid such as carbonic acid, HHC03, 

also written HzC03, formed by the solution of carbon dioxide (COz) in water. Ground water, found everywhere in 

rock openings at different depths beneath the land surface, contains dissolved carbon dioxide derived from decaying organic matter in soil, from the atmosphere, and 

from other sources. Even rainwater and snow contain a 

little carbon dioxide absorbed from the atmosphereenough to dissolve small amounts of limestone or of calcite 

cement from sandstone. The calcite cement in the Entrada and in many other sandstones is unevenly distributed, however, so that all the cement is removed first 

from places that contain the least amounts, and, once the 

cement is dissolved away, the loose sand is carried away 

by gravity, wind, or water. 

Both nearly flat but slightly irregular beds of sandstone 

and relatively thin walls or fins of sandstone are prime 

41 
targets for this differential erosion. Potholes, as shown 

in figure 18A, may be formed in relatively flat beds by the 

dissolving action of repeated accumulations of rainwater 

or snowmelt, even in arid regions like the Plateau. 

Relatively thin walls, or fins as they are called in parts 

of the Plateau including Arches, are targets for the formation of alcoves and caves by solution of cement and removal of sand by gravity, wind, and water, aided by the 

prying action of frost in joints, bedding planes, or other 

openings. Once a breakthrough of a wall or fin occurs, 

weakened chunks from the ceiling tend to fall, and natural 

arches of various shapes and sizes are produced. Arches 

form the strongest shapes for supporting overlying rock 

loads, as the rock in the arch is compressed toward each 

abutment by the heavy loads. Blocks of compressed rock 

beneath a relatively flat ceiling tend to be dislodged also 

by expansion due to release of pent-up pressure, until a 

strong self-supporting arch is formed. Release of pent-up 

pressure in rock walls may help also in initiating the 

formation of alcoves or caves in cliff faces. Man, including 

the ancient Greeks, Romans, Egyptians, and others, has 

long made use of arches in building bridges, aqueducts, 

temples, cathedrals, and other enduring edifices. 

As vividly shown in figure 12, the Entrada Sandstone 

on the northeast flank of the Salt Valley anticline has 

been broken by Earth forces into thin slabs mostly 10 to 

20 feet thick between nearly parallel joints, but, as will 

be noted in the descriptions of individual arches, some 

rock walls are only 1 or 2 feet thick, whereas others are 

50 feet thick or more. Some weak or thin slabs have 

weathered away, leaving the stronger or thicker ones as 

towering fins, particularly in the Fiery Furnace and Devils 

Garden areas. Jointing on a less spectacular scale also has 

broken the Entrada in areas south of Salt Valley, leaving 

walls or fins of rock. 

Although all the arches in the park were carved from 

the Entrada Sandstone, slight differences in their mode of 

origin or placement within the Entrada allow them to be 

grouped into three classes: (1) vertical arches formed in 

the Slick Rock Member alone or in the Slick Rock and 

42 
TUNNEL ARCH, reached by short trail north of main trail through 

Devils Garden. Opening is 26Vz feet wide and 22 feet high; span 

is about 14 feet thick. (Fig. 14) 43 
!:::. "BABY ARCH," just southwest of Sheep Rock in Courthouse Towers 

area. For details, see text. (Fig. 15) 

Moab Members, (2) vertical arches formed mainly in the 

Slick Rock Member but partly in, and with the aid of, 

the incompetent underlying Dewey Bridge Member, and 

(3) horizontal arches, or so-called pothole arches, formed 

from the union of a vertical pothole and a horizontal cave. 

Hereinafter, the three members will be referred to alone, 

without reference to the Entrada. 

Before giving examples of arches in each of the three 

classes, it is appropriate to remark that the arches and 

other erosion forms in the park represent but a fleeting instant in geologic time. Many of the pinnacles or piles of 

rock may be the broken remains of former arches, and 

many of the arches we see may be gone tomorrow, next 

BROKEN ARCH, reached by a ¥2-mile trail leading northward across [> 

field that separates Fiery Furnace from Devils Garden. White thinbedded unit at top is the Moab Member, which rests upon the 

massive salmon-.colored Slick Rock Member. Opening is 59 feet 

wide and 43 feet high. (Fig. 16) 

44 

year, or a few hundreds of years and, certainly, before 

many thousands of years. On the other hand, many new 

arches will form by the processes described above as the 

geologic clock ticks on. 

Examples of Arches 

Tunnel Arch (fig. 14) is a good example of an arch 

eroded entirely within the massive Slick Rock Member. 

Just southwest of Sheep Rock (fig. 31) is an unnamed 

opening in the lower part of the Slick Rock Member 

which I call "Baby Arch," because it is one of the newest 

ones visible from the park road (fig. 15). It is only 25~ 

feet wide and 14 feet high and penetrates a wall 14 feet 

thick. Note that the breakthrough probably began along 

the prominent recessed bedding plane at the base of the 

arch. Its youthfulness is also indicated by the sharp, 

angular breaks in the ceiling and by the pile of freshly 

fallen rocks. Some visitors have asked park personnel why 

they have not cleared away such debris! Despite its youthfulness, the ceiling has already taken on the shape of 

an arch. 

Broken Arch (fig. 16) was formed near the top of the 

Slick Rock Member and is strengthened and protected 

by the more resistant overlying Moab Member, which 

forms the upper half of the span. The crest is only 6 feet 

thick at the thinnest point and is not broken as the name 

seems to imply. 

Double Arch (fig. 17), "one" of the most beautiful in 

the park, is in The Windows section near the east end of 

the road. The southeast arch, which is 160 feet wide and 

105 feet high, is the second largest in the park, but the 

west arch measures only 60 feet wide and 61 feet high. In 

common with most arches in The Windows section, these 

two arches of the Slick Rock Member rest upon bases of 

the weak, easily eroded Dewey Bridge Member. More 

rapid erosion of the Dewey Bridge undercut the arches 

and hastened their development. 

The cause of the wavy bedding in the Dewey Bridge 

46 
DOUBLE ARCH, in The Windows section. (Fig. 17) 

47 
48 
PROBABLE STEPS IN' FORMATION OF POTHOLE ARCH. A, Or.iginal 

pothole probably formed in relatively level bed of sandstone, such 

as this one, which is in an older rock unit- the White Rim Sand~ 

stone Member of the Cutler Formation, a unit not present in Arches. 

This pothole, which contains 4 feet of water, is in nearby Canyonlands National Park (Lohman, 1974, fig. 17), just north of the edge 

of the White Rim, about 4V2 miles north of the confluence of the 

Green and Colorado Rivers. Photograph by E. N. Hinrichs. 8, Pothole is being deepened by solution while cliff is receding toward 

pothole by weathering. C, As erosion continues, pothole and cave 

in cliff face are growing deeper. D, Pothole Arch formed by union 

of vertical pothole and horizontal cave. £, Telephoto view of Pothole Arch from park road near stop 14. Visible span is 90 feet 

across and 30 feet high. (Fig. 18) 

49 
Member, as shown in figure 17 but as better shown in the 

frontispiece, is not known for sure but generally is regarded to be the result of irregular slumping during or 

just after deposition of the sediments in a body of water, 

caused by the weight of overlying sediments. 

The last example I shall take up is Pothole Arch (fig. 

18), which differs from all the other examples in that this 

arch is roughly horizontal rather than vertical. Most park 

visitors, including me, were not aware of this interesting 

feature until after publication of the pamphlet "The Guide 

to an Auto Tour of Arches National Park," which, as 

previously noted, may be purchased at the Visitor Center. 

Pothole Arch caps a ridge high above the road half a mile 

northwest of Garden of Eden, so only those who happened 

to look up at the right place were aware of its existence. 

A different mode of origin than that given in the caption for figure 18 is depicted on a poster in the Visitor 

Center, which shows the pothole being formed by a waterfall having an apparent flow rate of several cubic feet per 

second. Potholes can be formed in this manner in places 

where sufficient streamflow is available, either continuously or following rainstorms, but I believe the process 

depicted in figure 18 is a more likely mode of origin for 

Pothole Arch. 

-4-s APTLY STATED on a poster in the Visitor Center, 

how to see the park depends in part upon the question 

"How long can you stay?" Inasmuch as the park entrance 

and Visitor Center are beside a through U.S. Highway 

(163), many motorists first become aware of the park's 

50 
existence from the entrance sign, and some take time for 

at least a quick visit, such as a round trip to The Windows 

section, which can be made in an hour or so. 

For those who have or take more time and are able to 

walk at least short distances, a visit of 1 or 2 days is a 

very rewarding experience. Others, particularly avid 

shutter bugs and those with camping gear, profitably 

spend from several days to a week or more and hike all 

or most of the trails. 

Regardless of how long you plan to spend, I urge at 

least a brief stop at the Visitor Center, where excellent 

displays and a narrated slide show help materially in conveying just what the park has to offer. At the counter you 

can purchase a copy of "The Guide to an Auto Tour of 

Arches National Park," which explains the views from 

each of 25 numbered stops along the park road, as well 

as other reports describing arches or other parks and 

monuments. 

The park is open the year round, but, like most high 

deserts, it gets rather hot in the summer and cold enough 

in the winter for occasional snows and is sometimes closed 

temporarily because of heavy snowfall. The weather generally is ideal during the spring and fall. Even though 

summer daytime temperatures may exceed lOOoF (37.8°C) 

and slow down hikers, the nights are cool enough for comfortable sleeping beneath ample covers. 

Before beginning our trip through the park proper, let 

us consider a beautiful part many people fail to realize 

actually belongs to the park - the Colorado River canyon 

forming the southeastern boundary. 

51 
Colorado River Canyon 

:JHE SOUTHEASTERN BOUNDARY of the park for 

about 11 miles is the Colorado River, from the bridge on 

which U.S. Highway 163 crosses the river to a point upstream about half a mile below the mouth of Salt Wash. 

Illuminated night float trips down part of this reach are 

run during the summer, as noted on p. 16. Partly paved 

State Highway 128 follows the southeast side of the river 

for about 30 miles to Dewey Bridge, then goes northward 

about 15 miles to Cisco, where it connects with Highway 

I-70. 

The rocks of the Glen Canyon Group form the southernmost corner of the park, as shown in figure 19. About 2 

miles northeast of the bridge, we cross the axis of the 

Courthouse syncline (fig. 9), which brings the Navajo 

Sandstone down nearly to river level, as shown in figure 

20. The underlying Kayenta Formation is largely hidden 

by vegetation and alluvial deposits in this view. 

About 11 miles above the Moab bridge is the mouth of 

GLEN CANYON GROUP, forming southernmost point of park, as C> 

viewed across the Colorado River from State Highway 128 half a 

mile above Moab bridge carrying U.S. Highway 163. Massive sandstone forming about the lower third of cliff is the Wingate Sandstone, darker thin-bedded sandstones and mudstones forming 

middle section of cliff comprise the Kayenta Formation, upper cliff is 

the lower part of the Navajo Sandstone. Note that the saltcedar (tamarisk), which lines both banks of the river, is in full bloom. (Fig. 19) 

52 

NAVAJO SANDSTONE CLIFFS, bordering west bank of Colorado River in Courthouse syncline, from State Highway 128 

about 2 miles above the Moab bridge. Note rounded domes at top of cliff. (Fig. 20) 
Salt Wash (fig. 1), as viewed from State Highway 128. 

(See fig. 21.) Seventeen miles above the bridge (east of 

area shown in fig. 1), we get an excellent view of the 

southeast end of the highly faulted Cache Valley anticline, 

as shown in figure 22. The background shown in the 

MOUTH OF SALT WASH, viewed across Colorado River from point 

on State Highway 128, 11 miles above Moab bridge. Dark cliffs on 

upper right and left are of Wingate Sandstone capped by thin protective cover of resistant sandstone beds of the Kayenta Formation. 

In background Wingate is overlain by entire Kayenta Formation and 

lower part of the Navajo Sandstone. Wingate is underlain to river 

level by weathered slope of the Chinle Formation. Water in Salt 

Wash is largely backwater from the bankfull river; actual flow in 

wash generally is much less but at times reaches flood proportions. 

(Fig. 21) 

55 
SOUTHEAST END OF FAULTED CACHE VALLEY ANTICLINE, viewed 

northwestward across Colorado River from a point on State Highway 128, 17 miles above Moab bridge. High cliff of Wingate Sandstone on left is capped by thin protective layer of the Kayenta 

Formation. About upper third of slope below base of cliff is the 

Chinle Formation, below which is the Moenkopi Formation extending to high-water level. Note bent and broken beds on right. 

(Fig. 22) 

photograph formerly was the easternmost part of the 

former monument, but when the monument graduated to 

a park on November 16, 1971, this part of Cache Valley 

along with most of Dry Mesa was withdrawn from the 

park and put under the supervision of the Bureau of Land 

Management, also a part of the Department of the 

Interior. 

As noted on page 16, part of "Run, Cougar, Run" was 

filmed just upstream from the irrigated field in the foreground of figure 22, in a wide part of the valley called 

Professor Valley (fig. 7). This valley and the Richardson Amphitheater on the southeast side of the river were 

named after a Professor Richardson who settled in the 

area in the 1880's. The long abandoned townsite of 

Richardson was 1 ~ miles due east from the point from 

which figure 22 was taken. 

56 
,A. rea 

The junction of the park road with U.S. Highway 163 

is shown at the lower left of figure 23, and the entrance 

station, Visitor Center, parking lot, and several buildings 

are seen at the lower right. Several residences for park 

personnel and other buildings are shown in figure 25. As 

shown in the lower part of figure 23, the geology at the 

park entrance is rather complex, as the park boundary 

here is partly along the Moab fault and partly along a 

branch fault- both in the Seven Mile-Moab Valley 

anticline (fig. 7). The Moab fault extends northwestward 

from Moab for more than 30 miles (McKnight, 1940, 

p. 120, 121, pl. 1). 

As shown in figure 23, soon after leaving the checking 

station the park road begins to ascend the first of several 

switchbacks, and cuts first into the Slick Rock Member, 

then the Dewey Bridge Member, and finally the Navajo 

Sandstone the rest of the way to and beyond the top of 

the hill. 

From points a mile or so up the hill may be seen interesting features in several directions. 5 The view to the 

southwest is shown in figure 23, to the west are the Three 

Penguins (fig. 24). A good view of the Moab Valley is 

had by looking southeastward (fig. 25). A well in the 

Navajo Sandstone at the base of the hill supplies water 

to all the residences and to the Visitor Center, where a 

drinking fountain and modem restrooms are available to 

the public. Storage is provided by a steel tank hidden in a 

ravine above the buildings shown in figure 25. 

To the north the wall of Entrada Sandstone is cut by 

a normal fault (fig. 6), as shown in figure 26. 

'This is numbered stop 1 in the booklet referred to earlier "The Guide to 

an Auto Tour of Arches National Park," and corresponds to the numeral one 

on a small sign at the roadside parking place. Some of the other numbers are 

given in the pages that follow. 

57 
58 
<J FAULTED SEVEN MILE- MOAB VALLEY ANTICLINE. Top, View 

toward the southwest from park road about 1 mile above entrance 

station. Bottom, Geologic interpretation of photograph in part after 

McKnight (1940, pl. 1). Moab fault and branch fault (both normal 

faults, fig. 6) unite just beyond ridge of Slick Rock Member. Total 

vertical displacement along both faults is about 2,500 feet. H.F., 

unnamed upper member of Hermosa Formation; M.F., Moenkopi 

Formation; D, downthrown side of faults; U, upthrown side. Valley 

fill and slope wash of recent (Holocene) age obscure faults and 

underlying rocks. The original sequence of the rocks may be visualized by placing the Navajo Sandstone, the upper part of which 

is exposed at the lower right, on top of the Kayenta Formation, the 

lower few feet of which cap and protect the cliffs of Wingate Sandstone in the background. The Pacific Northwest (gas) Pipeline 

mentioned on page 15 is buried beneath the slice of the Moenkopi 

Formation between the two faults, which accounts for the disturbed 

appearance of the rock . (Fig. 23) 

6. THREE PENGUINS, viewed westward from park road about 1 mile 

above entrance station. Penguins are carved in massive Slick Rock 

Member seen resting upon thin-bedded Dewey Bridge Member. 

(Fig. 24) 

59 

<I MOAB VALLEY, viewed southeastward from park road about 1 mile 

above P.ntrance station. Moab fault in about middle of valley, hidden beneath recent (Holocene) valley fill and slope wash, separates 

unnamed upper member of Hermosa Formation just above U.S. 

Highway 163 on right from Navajo Sandstone forming hills on left 

and ledges in foreground. Park Service residences at base of hill. 

White patch bordering Colorado River on northwest is tailings pile 

of Atlas Corporation's uranium mill. Moab and Spanish Valley are 

beyond river, and south end of La Sal Mountains forms distant 

skyline. (Fig. 25) 

FAULTED WALL OF ENTRADA SANDSTONE, north of park road !::::. 

about 1 mile above entrance station. Fault is nearly vertical and 

normal (fig. 6), but fault trace slopes steeply downward to right, 

separating upthrown Slick Rock and Dewey Bridge Members on 

left from downthrown Slick Rock Member on right. Light-colored 

rock in foreground is Navajo Sandstone. Displacement probably 

does not exceed 50 feet. (Fig. 26) 

61 

Courthouse Towers Area 

-----:A:ooU.t-2~3-miles-from-the-entrance-station-is-a-turnoff~--­

and parking area at the south end of the Park Avenue 

trail (stop 2), which is about 1 mile long and ends at 

another parking area 1.7 miles farther north. An interesting hike is best made from south to north in a downhill 

direction, and hikers generally meet the cars of relatives 

or friends awaiting them at the northern parking area. The 

trail begins in a canyon cut in the soft Dewey Bridge 

Member and walled by high fins of the Slick Rock Member 

(fig. 27), but farther north the canyon is floored by the 

bare Navajo Sandstone. The avenue was named from the 

resemblance of the east wall to a row of tall buildings. 

Atop the west wall, just to the left of the view in figure 

27, are two balanced rocks (fig. 28). The one on the left, 

which resembles somewhat the head of an Egyptian queen, 

is offset to the right along a bedding plane, and this offset 

may have been caused by an earthquake. 

As we progress toward Courthouse Towers proper, lofty 

fins and monoliths lie mostly on our left, and to the right 

are fine distant views of the La Sal Mountains (stop 4). 

A general view of the Courthouse Towers is shown in 

figure 29, and closeups of two of the named rock sculptures 

- the Three Gossips and Sheep Rock - are shown in 

figures 30 and 31. Just beyond Sheep Rock, which some 

think resembles the Sphinx, we see "Baby Arch," shown 

in figure 15. 

Five miles from the entrance station, the road crosses 

Courthouse Wash on a modern bridge (stop 6) - a 

distinct improvement over the two tracks in the sand we 

used in 1946. The Courthouse syncline, named after the 

wash, extends northwestward through here. (See figs. 8, 

9, 20.) About a mile west of the bridge, Professor Stevens 

found another pothole arch. A mile and a half north of the 

bridge is stop 7, where attention is called in the booklet 

to the vast area of "petrified dunes" east of the road, 

which are simply dunelike exposures of the crossbedded 

<J PARK AVENUE, viewed to the north along trail. (Fig. 27) 

63 
BALANCED ROCKS ON SOUTH WALL OF PARK AVENUE, at south 

end of trail. (Fig. 28) 

64 
COURTHOUSE TOWERS, viewed to the northwest from point on 

park road about three-fourths of a mile northeast of the south end 

of Park Avenue trail. Sandstone towers are Slick Rock Member 

resting on Dewey Bridge Member, which also forms foreground. 

Three Gossips at upper left, Sheep Rock ·just beyond. The Organ 

and Tower of Babel are on right. (Fig. 29) 

65 
L. THE THREE GOSSIPS, shown at upper left of figure 29. (Fig. 30) 

SHEEP ROCK, shown on center-left skyline in figure 29. (Fig. 31) L. 

PETRIFIED SAND DUNES, looking northeast from park road 2.7 [> 

miles north of Courthouse Wash. The Navajo Sandstone was once 

a huge sandpile of dunes laid down by winds during an arid interval, so it is interesting to note that the irregularly weathered sandstone once again resembles a pile of crossbedded dunes. See also 

figure 35. (Fig. 32) 

Navajo Sandstone formed originally by the cementation 

of a vast area of sand dunes. My view of these was taken 

about 1 mile beyond the stop (fig. 32). 

West of the road between the petrified dunes and The 

Windows section, the Entrada Sandstone, particularly the 

Dewey Bridge Member, has been weathered into grotesque 

spires and pinnacles resembling the so-called "hoodoos and 

goblins" in Goblin Valley State Park, just north of Hanksville, Utah. Typical examples of "hoodoos and goblins" are 

66 

"HOODOOS AND GOBLINS," weathered from Dewey Bridge Member, 

viewed northwest from park road about 2112 miles north of Courthouse Wash. (Fig. 33) 

shown in figure 33 (near stop 8). It seems reasonable to 

assume that some of these spires are the skeletal remains 

of former arch abutments. From here may be seen North 

and South Windows and Turret Arch on the skyline to 

the northeast (figs. 37-40) . 

The Windows Section 

The Windows section, one of the most beautiful parts 

of the park, once was the only readily accessible part of 

the former monument and is still the only collection of 

arches seen by many visitors who either do not have or do 

not take time to travel farther north. All the arches and 

erosion forms are on or near a high crest called Elephant 

Butte (Dane, 1935, p. 126, 127), which separates Salt 

Valley from the Courthouse syncline. The ridge also marks 

the south edge of several minor anticlines and synclines 

termed by Dane the "Elephant Butte folds." 

68 
Guarding the approach to The Windows section is 

Balanced Rock (stop 9). As shown in the frontispiece, it 

is accompanied on the right by another balanced rock and 

a third one may be seen in the distance. The original route 

to The Windows section, pioneered by Goulding, passed 

just north of Balanced Rock. Traces of the old road between here and the Garden of Eden parking area are still 

visible but no longer used. To the west, however, a part 

of the old road is the starting point of a jeep trail leading 

northwestward through Herdina Park to a point near 

Klondike Bluffs, where it joins the dirt road in Salt Valley 

(fig. 1). Visitors having four-wheel-drive vehicles may 

wish to drive at least as far as Eye of The Whale (fig. 34), 

EYE OF THE WHALE, one of several arches in Herdina Park, just 

south of jeep trail about 2 miles northwest of Balanced Rock. Cut 

in Slick Rock Member. Front opening is 60 feet wide and 27 feet 

high, but back opening is only 35 feet wide and 11 feet high. Photograph by Professor Dale J. Stevens, Brigham Young University. 

(Fig. 34) 

69 
INTRICATE CROSSBEDS IN NAVAJO SANDSTONE, on north side 

of road between Garden of Eden and Cove of Caves. Red crest is 

basal part of Dewey Bridge Member. (Fig. 35) 

which is about 2 miles northwest of Balanced Rock. There 

are several picnic tables at the beginning of this jeep trail, 

but no water. 

Just beyond Balanced Rock, a branch paved road turns 

eastward 2 ~ miles to the main parking lots in The 

Windows section. Between the Garden of Eden (stop 13) 

and Cove of Caves are spectacular exposures of the 

Navajo Sandstone showing the crossbedding typical of the 

original dunes (fig. 35). Just east of the crossbedded 

Navajo Sandstone, shown in figure 35, we pass Cove Arch 

and Cove of Caves (stop 10) on the north side of the 

road (fig. 36). 

Just around the curve east of Cove of Caves is the first 

of two parking lots (stop 11) forming a one-way loop at 

the end of this branch of the road. From the loop may be 

seen the greatest concentration of readily accessible arches 

70 
COVE ARCH AND COVE OF CAVES, on north side of road just west 

of Double Arch and Parade of Elephants. Arch at left and three of 

the caves on right are roofed by Slick Rock Member and floored by 

Dewey Bridge Member. Arch is 481!2 feet wide and 34 feet high. 

In time the caves will eat through the 30-foot-thick fin and become 

arches. Note sharp contact between Dewey Bridge Member and 

Navajo Sandstone. (Fig. 36) 

in the park, all of which are roofed by the Slick Rock 

Member and floored by the Dewey Bridge Member. Let 

us take the short paved trail from the upper lot to the 

southeast, where we come first to North Window (fig. 37). 

If we walk through this arch and climb the rock beyond 

(fig. 37 caption), we see one of the best views in the park 

(fig. 38). A short walk south of North Window brings us 

to South Window (fig. 39) . The other side of this arch 

may be reached either by walking around the nearby 

southeast end of the fin or by walking through North 

Window. A short walk to the southwest brings us to 

Turret Arch - the one seen through North Window in 

figure 38. Figure 40 was taken from the southwest side 

of Turret Arch, viewed northeastward toward South 

Window, one corner of which appears at the left. Both 

North and South Windows may be seen in one photograph 

taken from points near Turret Arch. 

71 
NORTH WINDOW, viewed to the northeast. Large rock seemingly 

partly blocking left end of arch actually is the southeast end of a 

fin some 50 feet or more beyond the arch, from which figure 38 

was taken. Arch is 93 feet wide and 51 feet high. (Fig. 37) 

From the lower parking lot (stop 12), a short walk by 

paved trail takes us to spectacular Double Arch, shown in 

figure 17. This arch is visible from the parking lot but is 

best seen and photographed from at or near the end of the 

trail. Looking westward from near the trail's end, we see 

the Parade of Elephants, shown in figure 41. This feature 

is described on pages 16 and 17 of "The Guide to an Auto 

Tour of Arches National Park" as "whimsical stone 

statuary resembling a circus pachyderm parade. With tail 

in trunk, the elephants rumble toward you along a sandstone roadway." 

Ribbon Arch, on the north side of Elephant Butte, is one 

of the most delicate ones in the park (fig. 1). Although it 

is 50 feet wide and 55 feet high, the rock span is only 

1 Y2 feet wide and 1 foot thick. 

72 
On the way back to the intersection with the main park 

road, we pass stop 14, from which may be seen Pothole 

Arch (fig. 18). One and one-half miles north of the intersection with the main road is the Panorama Point parking 

area (stop 15), which affords fine distant views of Salt 

and Cache Valleys and points beyond. A roadside exhibit 

portrays the gradual development of the Salt Valley anticline, which supplements my description on pages 27-32. 

A parking space a short distance farther down the hill 

(stop 16) provides good distant views of the Fiery Furnace. I tried several telephoto shots from this viewpoint, 

but preferred my closeup views, such as the one shown in 

figure 44. 

LOOKING SOUTHWESTWARD THROUGH NORTH WINDOW, from 

fin shown beyond left side of North Window in figure 37. Turret 

Arch (fig. 40) is seen at right middle ground, south rim of Moab 

Valley to left of arch, Colorado River canyon forms left skyline. 

(Fig. 38) 
SOUTH WINDOW, viewed toward northeast. Arch is 105 feet wide 

and 66 feet high. See text. (Fig. 39) 

Delicate Arch Area 

Two and a half miles northeast of the road intersection 

near Balanced Rock, a gravelled side road leads northeastward to several points of considerable interest. The 

photograph in figure 11 was taken from this side road 

about half a mile northeast of the intersection. About 2 

miles to tqe northeast, just beyond Salt Valley Wash, is 

a parking area (stop 17) at the beginning of the trail past 

Wolfe's Bar-DX Ranch (fig. 3) to famed Delicate Arch, 

which is featured on the front cover. Although the trail 

to the arch is only 1 ~ miles long, it crosses several hills 

at the outset, then climbs 500 feet, mostly on bare Entrada 

Sandstone, so is considered quite strenuous, particularly 

74 
TURRET ARCH, viewed northeast toward South Window, part of 

which is visible on left. Small opening on right is visible also in 

figure 38. Largest arch is 39 feet wide and 64 feet high; smaller 

one is 12 feet wide and 13 feet high. A still smaller one, not visible 

in the photograph, is 8 feet wide and only 41/2 feet high. (Fig. 40) 

in hot weather. The Park Service advises hikers to carry 

water. The Walt Disney crew, cameras, gear, cougars, and 

all climbed this trail in the hottest part of the summer of 

1971 (see p. 16), while my wife and I were working in 

the vicinity. Visitors who do not wish to make the hike 

may get a distant view of Delicate Arch by driving to a 

parking area (stop 18) 1.3 miles farther east. 

After leaving Wolfe's Ranch, the trail to Delicate Arch 

crosses Salt Wash on a suspension foot bridge (fig. 42). 

Just beyond the bridge, a short walk to the left (north) 

leads to the Ute petroglyphs shown in the lower photograph of figure 2. The most difficult part of the trail, on 

75 

bare sandstone, is marked by cairns of stones placed at 

sufficient intervals to keep hikers from losing the barely 

visible trail. When the summit finally is reached and the 

last comer rounded, one suddenly sees perhaps the most 

sublime view in the park-famed Delicate Arch, framing 

part of the La Sal Mountains beyond (fig. 43). This 

graceful arch and mighty Landscape Arch (fig. 53) were 

considered to be in serious jeopardy during the era of 

sonic booms, but hopefully this danger now is past. (See 

p. 16-17.) 

It may be of interest to shutterbugs that professional 

photographer Hal Rumellugged an 8- X 10-inch camera 

plus a heavy tripod and accessories up the steep trail to 

get the excellent photograph of Delicate Arch shown in 

figure 43. The late afternoon sun intensified the red somewhat, but my shots made earlier in the day using both 

4- X 5-inch and 35-mm equipment resulted in unwanted 

shadows, even though the salmon color of the Slick Rock 

Member was more nearly normal. 

After leaving the junction with the side road, the main 

park road traverses slices of vertical strata squeezed between faults along the north side of Salt Valley, then 

gradually climbs out of the valley for about 2 miles to a 

parking area (stop 19), from which good views are had of 

the southeast end of Salt Valley and of the grabens in the 

west end of Cache Valley. (See fig. 11.) 

<J PARADE OF ELEPHANTS, viewed west from end of trail to Double 

Arch. Two elephants are on right, one on left. (Fig. 41) 

77 
D. SUSPENSION FOOT BRIDGE ACROSS SALT WASH, in front of 

Wolfe's cabin at beginning of Delicate Arch trail. (Fig. 42) 
Fiery Furnace 

About half a mile farther uphill is a parking area for 

viewing the southeastern part of the Fiery Furnace (stop 

20) , a vast array of towering fins and pinnacles of the 

reddish Slick Rock Member separated by narrow slots, 

vaguely resembling flames shooting skyward. The view of 

the Fiery Furnace in figure 44 was taken about 1 mile 

farther up the hill. It is not difficult to get lost among this 

myriad of fins and narrow slots, so ranger-guided tours 

are conducted during the summer. 

About 1 mile farther northwest is a parking area (stop 

23) from which a short walk to the north end of Fiery 

Furnace leads to a narrow slot between high fins (fig. 45), 

along which a short sandy trail leads to a recess along the 

southwest wall containing Sand Dune Arch (fig. 46). This 

hidden arch receives sunshine only near the middle of the 

day and is a delightful, shady place to rest. 

From the entrance to the slot leading to Sand Dune 

Arch, a trail goes half a mile north across an open field to 

Broken Arch, shown in figure 16. This field, which separates the Fiery Furnace and Devils Garden areas, is seen 

from the air in figure 12. 

<J DELICATE ARCH, from end of trail P/2 miles above Wolfe's Ranch . 

The opening is 33 feet wide and 45 feet high. The left abutment 

is only 5 feet wide at the narrowest point. The arch is carved near 

the top of the Slick Rock Member, and the top of the span, 19 

feet thick, is capped by a few feet of the more resistant Moab 

Member, as is Broken Arch (fig. 16). Photograph by Hal Rumel, 

Salt Lake City. (Fig. 43) 

79 
FIERY FURNACE, viewed northwest along park road about 1 mile northwest from stop 20. Fins and spires are of the jointed 

Slick Rock Member (fig. 12), but the top of the Dewey Bridge Member is seen to the right of the curve in the road. (Fig. 44) 
TRAIL TO SAND DUNE ARCH, looking northwest away from arch, 

between towering fins of Slick Rock Member, at northwest end 

of Fiery Furnace. Southeast end of Devils Garden in distance. 

(Fig. 45) 

81 
SAND DUNE ARCH, in recess along southwest wall of narrow slot 

shown in figure 45. Slick Rock Member. (Fig. 46) 

Salt Valley and Klondike Bluffs 

Before proceeding to the end of the paved road, let us 

take an unimproved side road, which turns south about a 

third of a mile beyond the last stop, in order to see more 

of Salt Valley and to visit Klondike Bluffs in the northwestern part of the park. After descending 2.3 miles of 

winding road we reach the normally dry bed of Salt Valley 

Wash, and turn abruptly to the northwest. For the next 

three-fourths of a mile the "road" is simply two tracks in 

the loose, sandy bed of the wash, which obviously should 

not be travelled when flooded or when there is even a 

hint of rain. In dry weather, however, this road may be 

travelled by ordinary passenger car. This stretch of the 

wash cuts through an intruded block of the Paradox 

Member of the Hermosa Formation consisting mainly of 

gray and brown gypsum, the common salt having been 

82 
dissolved out by ground water. Such an intrusive block of 

salt-bearing rock is known to geologists as a diapirnot to be confused with the garment (diaper) worn by 

infants. 

From here on the road traverses a rather uninteresting 

stretch of valley north of Salt Valley Wash. Eleven miles 

from tlle starting point, the -road reaches an intersection 

from which a side road leads southwestward three-fourths 

of a mile to a parking area at the foot of Klondike Bluffs, 

which form the south side of Salt Valley. From here, one 

may make a strenuous hike over a primitive trail about 

1 )2 miles long to beautiful Tower Arch (fig. 47). 

The valley road continues northwestward from the intersection to and beyond the northwest end of the park and 

connects with roads to Crescent Junction, Thompson, and 

the Yellow Cat mining district, north of the park (p. 14). 

Let us return to the paved road and continue our tour 

of the park. 

De vi Is Garden 

Turning left (northwest) at the intersection with the 

paved park road, we enter Devils Garden- another large 

maze of towering red fins separated by narrow slots, which 

resembles the Fiery Furnace. After a third of a mile, we 

reach stop 24 and walk 100 feet or more to the north for a 

good view of Skyline Arch (fig. 48). This arch is very 

appropriately named, as it forms the skyline viewed either 

from the road on the south or from the campground on 

the north, from points south of the amphitheater. Less 

well known is the fact that Skyline Arch is clearly visible 

to the naked eye or through binoculars from stretches 

of Highway I-70 (or old U.S. Highways 6 and 50) about 

11 miles to the north. Most arches and other erosion forms 

do not change appearance much from day to day or year 

to year, but some, like "Baby Arch" (fig. 15), show evidence of relatively recent origin. In November 1940 

(Abbey, 1971, p. 42) Skyline Arch suddenly doubled in size 

by the fall of a large rock that occupied what is now the 

northwest half of the arch. Photographs taken before and 

83 
D. TOWER ARCH, on Klondike Bluffs, viewed eastward. Arch is in 

Slick Rock Member but tower on left, after which arch was named, 

is capped by a protective layer of the resista.nt Moab Member. 

Opening is 88 feet wide and 43 feet high. Photograph by Robert D. 

Miller. (Fig. 47) 

SKYLINE ARCH, viewed north from point about 100 feet north of C> 

stop 24, in Slick Rock Member. Although fins are vertical, note 

that the strata seem to dip about 15° to the right, although the 

actual dip is to the northeast. (See fig. 50.) (Fig. 48) 

84 

after this event appear on pages 24 and 25 of the road 

guide and also in the museum at the Visitor Center. 

Another half mile brings us to a one-way (to right) loop 

at the end of the park road. Just beyond the beginning 

of the loop is a parking lot and very attractive picnic 

area containing several picnic tables shaded by pinon 

pines at the foot of a towering red fin of the Slick Rock 

Member. Just north of this picnic ground, a paved side 

road leads eastward into a truly beautiful, well-equipped 

campground comprising both back-in and drive-through 

campsites for trailers, campers, or tents; three pairs of 

modem restrooms, hydrants, and drinking fountains; and 

an amphitheater, where illustrated campfire talks are 

given nightly during the summer. The east end of the 

campground is shown in figure 49. 

Devils Garden in general and the campground in particular are on the crest of a ridge separating Salt Valley to 

the southwest from the Sagers Wash syncline to the northeast, which lies north of Yellow Cat Flat and north of the 

CAMPGROUND IN DEVILS GARDEN, viewed northwestward across 

turn-around at southeastern end. (Fig. 49) 
VIEW NORTH FROM CAMPGROUND, in late afternoon. Reddish 

Slick Rock Member capped by light-colored Moab Member are 

seen dipping northeastward toward Sagers Wash syncline. Book 

Cliffs, north of Thompson, are 16 miles north on left skyline. 

(Fig. 50) 

area shown in figure 1. From the higher parts of the campground striking views are to be had toward the north and 

northeast, particularly late in the afternoon, as shown in 

figure 50. 

In about the middle of the one-way loop at the end of 

the park road is a well that supplies water to the campground from early in the spring until the return of freezing 

weather late in the fall. The well, which was drilled in 

1962 to a depth of 900 feet, obtains a small amount of 

water from the Wingate Sandstone. No water was found in 

the overlying Navajo and Entrada Sandstones because of 

the pronounced dip of the rocks toward the northeast, 

which allows any water in these rocks to drain northeastward (Ted Arnow, written commun., 1963). Water from 

this well is pumped to a steel tank in a high part of the 

87 
SOUTHEASTERN PART OF DEVILS GARDEN TRAIL, viewed northwestward. Narrow slot between fins of Slick Rock Member indicates 

local spacing of joints. (Fig. 51) 

campground, whence it flows by gravity to the three sets 

of restrooms. 

At the northwest end of the one-way loop is a large 

parking area for use by people hiking the Devils Garden 

trail. This trail leads to seven of the most interesting 

arches in the park, all of which are in the Slick Rock 

Member, and there are many more farther to the northwest. The approximate distances to the seven arches are 

given in the paragraphs that follow. The trail is paved 

for about 1 mile as far as Landscape Arch (fig. 53), but 

88 
PINE TREE ARCH, viewed northeastward. Opening is 46 feet wide 

and 48 feet high. Fin is 30 feet thick. (Fig. 52) 

89 
from there to Double 0 Arch (fig. 56) the trail is primitive, and the Park Service recommends rubber soles as 

part of the trail is on bare sandstone. For these reasons, 

many visitors hike only as far as Landscape Arch. 

Much of the trail, particularly the first part, lies in a 

narrow slot between fins of the Slick Rock Member, as 

shown in figure 51. After about half a mile, a side trail 

to the north leads to a Y, the right-hand fork of which 

goes to Tunnel Arch (fig. 14). The left-hand fork leads to 

Pine Tree Arch, obviously named for the pi:fion pine 

framed by this arch (fig. 52) . 

At the end of the improved part of the trail, we reach 

Landscape Arch (fig. 53), claimed by the Park Service to 

be the longest known natural arch in the world. According 

to Ouellette (1958) it is 291 feet long and 118 feet high, 

but Professor Stevens' measurements indicate it to be 287 

feet long and 106 feet high. At its thinnest point on the 

right, the span is only 11 feet wide and 11 feet thick. In 

1958 three young men made what was claimed to be the 

second known ascent of Landscape Arch, using ropes and 

other climbing gear, after which they walked across (Ouellette, 1958). This crossing was made with the permission 

of a park ranger, but such permission is no longer given, 

for the safety of both the arch and of would-be climbers. 

Wall Arch is about a quarter of a mile beyond the end 

of the improved part of the trail, and another three-fourths 

mile brings us to Navajo Arch (fig. 54) and Partition Arch 

(fig. 55). A distant view of Partition Arch may be had 

just before reaching Landscape Arch. Part of the remaining trail to Double 0 Arch (fig. 56) is on the top of a low 

sandstone fin, in part between somewhat higher fins and 

in part above lower slots. 

LANDSCAPE ARCH, viewed southwestward from near end of im- [> 

proved part of Devils Garden trail. Note that ground beneath arch 

is covered by slope wash and near the middle with what appears 

to be a small landslide. Slick Rock Member here is more nearly 

buff than salmon colored, because of a smaller content of iron 

oxide. Fresh breaks and angular blocks of stone at right abutment 

indicate relatively recent rock falls. See text for size. (Fig. 53) 

90 

/'::, NAVAJO ARCH, viewed northeastward from a branch of Devils Garden trail. One of few arches having a flat soil-covered floor. Opening is 401/2 feet wide. Photograph by National Park Service. 

(Fig. 54) 

DOUBLE 0 ARCH , viewed about north from northwest end of Devils [> 

Garden trail. Large opening is 71 feet wide and 45 feet high; small 

one at lower left is 21 feet wide and 11 feet high. Span of large 

opening is 11 feet wide and 6 feet thick . Arch frames a part of the 

Book Cliffs about 14 miles to the north. Photograph by Hildegard 

Hamilton, Flagstaff, Ariz. (Fig. 56) 

Beautiful Double 0 Arch (fig. 56) is at the end of the 

Devils Garden trail about 2~ miles northwest of the trailhead. About half a mile northwest of the trail's end is a 

prominent landmark called Dark Angel (fig. 57), which is 

visible in figure 12 and from the unimproved road in Salt 

Valley. 

92 
!::::. PARTITION ARCH, viewed southwestward from near Devils Garden 

trail. Arch frames part of south wall of Salt Valley and, on skyline, 

mesas south of Moab Valley. Opening is 27¥2 feet wide and 26 feet 

high. A smaller opening to the right measures 8¥2 feet wide and 

8 feet high. Photograph by Dawn E. Reed. (Fig. 55) 

<J DARK ANGEL, a shaft of the Slick Rock Member that is an erosional remnant of a once high, narrow fin. About one-half mile 

northwest of Double 0 Arch. Photograph by National Park Service. 

(Fig. 57) 

"INDIAN-HEAD ARCH," in upper Devils Garden. Arch and most of!:::, 

head are in Slick Rock Member, top of head is basal part of Moab 

Member. Opening is 4 feet wide and 4112 feet high. Photograph by 

Professor Dale J. Stevens, Brigham Young University. (Fig. 58) 

GEOLOGIC TIME SPIRAL (overleaf), showing the sequence, names, r> 

and ages of the geologic eras, periods, and epochs, and the evolution of plant and animal life on land and in the sea. The primitive 

animals that evolved in the sea during the vast Precambrian Era 

left few traces in the rocks because they had not developed hard 

parts, such as shells, but hard shell or skeletal parts became 

abundant during and after the Paleozoic Era. (Fig. 59) 

95 


Professor Stevens found 14 arches in what he called 

upper Devils Garden, northwest of Double 0 Arch, and 

two arches in the northwesternmost extension of the park 

known as Eagle Park (fig. 1). One of the unnamed arches 

in upper Devils Garden is shown in figure 58. I am tentatively calling it "Indian-Head Arch," because of the rather 

obvious resemblance. 

This ends our journey through Arches National Park, 

but there remains for consideration a summary of the 

principal geologic events leading to the formation of this 

beautiful part of the Colorado Plateau and a brief comparison with the geology of other national parks and 

monuments on the Plateau. 

fi A VING FINISHED our geologic trip through Arches 

National Park, let us see how the arches and other features 

fit into the bigger scheme of things- the geologic age 

and events of the Earth as a whole, as depicted in figure 

59. As shown in figure 4, the rock strata still preserved 

in the park range in age from Pennsylvanian to Cretaceous, 

or from about 300 million to 100 million years old- a 

span of about 200 million years. This seems an incredibly 

long time, until one notes that the earth is some 4.5 billion 

years old, and that our rock pile is but 1/ 23 or 4~ percent 

of the age of the Earth as a whole. Thus, in figure 59, the 

rocks exposed in the park occupy only about the left half 

of the top whorl of the spiral. 

But this is not the whole story. As indicated earlier, 

younger Mesozoic and Tertiary rocks more than 1 mile 

thick that once covered the area have been carried away 

98 
by erosion, and if we include these the span is increased 

to about 250 million years, or nearly a full whorl of 

the spiral. 

Deep tests for oil and gas tell us that much older rocks 

underlie the area, and we have seen that some of these 

played a part in shaping the park we see today. In addition to the Precambrian igneous and metamorphic rocks, 

there is about 2,000 feet of Paleozoic sedimentary rocks 

older than the Pennsylvanian Paradox Member of the 

Hermosa Formation, most of which was laid down in ancient seas. This includes strata of Cambrian, Ordovician, 

Devonian, Mississippian, and Pennsylvanian ages (fig. 

59). There are some gaps in the rock record caused by 

temporary emergence of the land above sea level and 

erosion of the land surface before the land again subsided 

below sea level so that deposition could resume. Silurian 

rocks are absent, presumably because, here, the Silurian 

Period was dominated by erosion rather than deposition. 

While Pennsylvanian and Permian rocks were being 

laid down in and southwest of the park, a large area to 

the northeast, called by geologists the Uncompahgre Highland (because it occupied the same general area as part 

of the present Uncompahgre Plateau), rose slowly above 

sea level. Whatever Paleozoic rocks were on this rising 

land plus part of the underlying Precambrian rocks were 

eroded and carried by streams into deep basins to the 

northeast and southwest. Thus, while some marine or nearshore deposits were being laid down in and south of the 

park, thousands of feet of red beds were being laid down 

by streams between the park and what is now the Uncompahgre Plateau. During part of Middle Pennsylvanian 

time, a large area, including the park, known as the Paradox basin, was alternately connected to or cut off from the 

sea, so that the water was evaporated during cutoff periods and replenished during periods when connection with 

the sea resumed. In these huge evaporation basins were 

deposited the salt and gypsum plus some potash salts and 

shale that now make up the Paradox Member of the 

Hermosa Formation. 

Arches National Park contains four northwesterly trend99 
ing major folds - the Salt Valley and Cache Valley salt 

anticlines, the Courthouse syncline, and the faulted MoabSeven Mile anticline, which forms the southwestern border. 

How these folds were formed was explained on pages 27-32. 

The history of their growth, however, was a long one 

that began about 300 million years ago in the Pennsylvanian and ended about 50 million years ago in the early 

Tertiary. The growth of these folds occurred in two stages. 

The first stage, which involved the development of the salt 

cores of the anticlines, ended in the Jurassic with the 

beginning of Morrison time; the second stage, which involved additional folding that intensified the magnitude 

and shape of existing folds, occurred in the early Tertiary 

and was followed later by collapse of the salt anticlines. 

The formation and collapse of the Salt Valley and Cache 

Valley anticlines was accompanied by pronounced jointing 

(fig. 12), which allowed differential erosion to produce the 

tall fins in which the arches were formed. 

The old Uncompahgre Highland continued to shed 

debris into the bordering basins until Triassic time, when 

it began to be covered by a veneer of red sandstone and 

siltstone of the Chinle Formation (Lohman, 1965). The 

area remained above sea level during the Triassic Period 

and most, if not all, of the Jurassic Period, although the 

Jurassic Carmel Formation was laid down in a sea that 

lay just to the west. 

Late in the Cretaceous Period a large part of Central 

and Southeastern United States, including the eastern 

half of Utah, sank beneath the sea and received thousands 

of feet of mud, silt, and some sand that later compacted 

into the Mancos Shale. This formation, as well as all 

younger and some older strata, has long since been eroded 

from most of the park area, but a little of the Mancos is 

preserved in the Cache Valley graben (fig. 11) , and the 

entire Mancos Shale and younger rocks are present in 

adjacent areas, such as the Book Cliffs north of Green 

River, Crescent Junction, and Cisco (figs. 7, 50, 56). 

The land rose above the sea at about the close of the 

Cretaceous and has remained above ever since, although 

inland basins and lakes received sediment during parts 

100 
of the Tertiary Period. Compressive forces in the Earth's 

crust produced some gentle folding of the strata at the 

close of the Cretaceous, but more pronounced folding and 

some faulting occurred during the Eocene Epoch, when 

most of the Rocky Mountains took form. During the Miocene Epoch igneous rock welled up into older rocks to 

form the cores of the nearby La Sal, Abajo, and Henry 

Mountains. Additional uplift and some folding occurred 

in the Pliocene and Pleistocene Epochs. 

Much of the course of the Colorado River was established during the Miocene Epoch, with some additional 

adjustments in the late Pliocene and early Pleistocene 

Epochs (Hunt, C. B., 1969, p. 67). Erosion during much 

of the Tertiary Period and all of the Quaternary Period 

plus some sagging and breaking of the crest of the anticlines, brought on by solution and lateral squeezing of salt 

beds beneath the Moab-Seven Mile, Salt Valley, and 

Cache Valley anticlines, combined to produce the landscape as we now see it. 

The Precambrian rocks beneath the area are about 1.5 

billion years old; so an enormous span of time is represented by the rocks and events in and beneath Canyonlands National Park. 

If we consider the geologic formations that make up the 

national parks (N.P.), national monuments (N.M.) (excluding small historical or archaeological ones), Monument Valley, San Rafael Swell, and Glen Canyon National 

Recreation Area, all in the Colorado Plateau, it becomes 

apparent that certain formations or groups of formations 

play starring roles in some parks or monuments, some play 

supporting roles, and in a few places the entire cast of 

rocks gets about equal billing. Let us compare them and 

see how and where they fit into the "Geologic Time 

Spiral" (fig. 59) . 

Dinosaur N.M., with exposed rocks ranging in age from 

Precambrian to Cretaceous, covers the greatest time span 

(nearly 2 billion years), but has one unit- the Jurassic 

Morrison Formation- in the starring role, for this unit 

contains the many dinosaur fossils that give the monument its name and fame, although there are several older 

101 
units in supporting roles. Grand Canyon N.P. and N.M. 

are next, with rocks ranging in age from Precambrian 

through Permian (excluding the Quaternary lava flows 

in the N.M.), but here there is truly a team effort, for 

the entire cast gets about equal billing. Canyonlands N.P. 

stands third in this category, with rocks ranging from 

Pennsylvanian to Jurassic, but we would have to give 

top billing to the Permian Cedar Mesa Sandstone Member 

of the Cutler Formation, from which The Needles, The 

Grabens, and most of the arches were sculptured; the Triassic Wingate Sandstone and the Triassic(?) Kayenta 

Formation get second billing for their roles in forming and 

preserving Island in the Sky and other high mesas. 

Now let us consider other areas with only one or few 

players in the cast, beginning at the bottom of the time 

spiral. Black Canyon of the Gunnison N.M., cut entirely 

in rocks of early Precambrian age with only a veneer of 

much younger rocks, obviously has but one star in its 

cast. Colorado N.M. contains rocks ranging from Precambrian to Cretaceous- equal to Dinosaur in this respect, but Colorado is unique in that all the rocks of the 

long Paleozoic Era and some others are missing from the 

cast; of those that remain, the Triassic Wingate and the 

Triassic(?) Kayenta are the stars, with strong support 

from the Jurassic Entrada Sandstone. 

All the bridges in Natural Bridges N.M. were carved 

from the Permian Cedar Mesa Sandstone Member of the 

Cutler Formation, also one of the stars in Canyonlands 

N.P. In Canyon de Chelly (pronounced dee shay) N.M. 

and Monument Valley (neither a national park nor a 

national monument, as it is owned and administered by 

the Navajo Tribe), the De Chelly Sandstone Member of 

the Cutler Formation- a Permian member younger than 

the Cedar Mesa - plays the starring role. 

Wupatki N.M. near Flagstaff, Ariz., stars the Triassic 

Moenkopi Formation. Petrified Forest N.P. (which now 

includes part of the Painted Desert) has but one starthe Triassic Chinle Formation, in which are found many 

petrified logs and stumps of ancient trees. The TriassicJurassic Glen Canyon Group (fig. 19), which includes the 

102 
Triassic Wingate Sandstone, the Triassic(?) Kayenta 

Formation, and the Triassic(?) -Jurassic Navajo Sandstone, receives top billing in recently enlarged Capitol Reef 

N.P., but the Triassic Moenkopi and Chinle Formations 

enjoy supporting roles. 

The Triassic(?) -Jurassic Navajo Sandstone, which has 

a supporting role in Arches N.P., is the undisputed star 

of Zion N.P., Rainbow Bridge N.M., and Glen Canyon 

National Recreation Area, despite the fact that the latter 

is the type locality of the entire Glen Canyon Group. The 

1'i11vajo also forms the impressive reef at the east edge of 

the beautiful San Rafael Swell, a dome, or closed anticline, 

now crossed by Highway 1-70 between Green River and 

Fremont Junction, Utah. 

As we journey upward in the time spiral (fig. 59), we 

come to the Jurassic Entrada Sandstone, which stars in 

Arches N.P., with help from the underlying Navajo Sandstone, and a supporting cast of both older and younger 

rocks. The Entrada also forms the grotesque erosion forms 

called "hoodoos and goblins" in Goblin Valley State Park, 

north of Hanksville, Utah. 

Moving ever upward in the spiral, we come to the Cretaceous- the age of the starring Mesaverde Group, in 

which the caves of Mesaverde N.P. were formed, and 

which now house beautifully preserved ruins once occupied 

by the Anasazi, the same ancient people who once dwelt 

in Arches N.P. and nearby areas. 

This brings us up to the Tertiary Period, during the 

early part of which the pink limestones and shales of the 

Paleocene and Eocene Wasatch Formation were laid down 

in inland basins. Beautifully sculptured cliffs, pinnacles, 

and caves of the Wasatch star in Bryce Canyon N.P. and 

in nearby Cedar Breaks N.M. This concludes our climb 

up the time spiral, except for Quaternary volcanoes and 

some older volcanic features at Sunset Crater N.M., near 

Flagstaff, Ariz. 

Thus, one way or another, many rock units formed 

during the last couple of billion years have performed on 

the stage of the Colorado Plateau and, hamlike, still lurk 

in the wings eagerly awaiting your applause to recall them 

103 
to the footlights. Don't let them down -visit and enjoy 

the national parks and monuments of the Plateau, for 

they probably are the greatest collection of scenic wonderlands in the world. 

mANY REPORTS covering various aspects of the 

area have been cited in the text by author and year, and 

these plus a few additional ones are listed in "Selected 

References." A few works of general or special interest 

should be mentioned, however. 

Between 1926 and 1929 the entire area now included 

in the park was mapped geologically in classic reports by 

Dane (1935) and by McKnight (1940). These men and 

their field assistants mapped the area by use of the planetable and telescopic alidade without benefit of modem 

topographic maps or aerial photographs, except for topographic maps of the narrow stretch along the Colorado 

River mapped under the direction of Herron (1917). Only 

small sections could be reached by automobile, so nearly 

all the area was traversed using horses and mules or by 

hiking. This work plus mapping done in nearby areas to 

the south and to the north (Stokes, 1952) during the 

uranium boom of the mid-fifties was used by Williams 

(1964) in compiling a geologic map of the Moab quadrangle at a scale of 1: 250,000. 

Several early reports on the Colorado River and its 

potential utilization contain a wealth of information and 

many fine photographs, including two by La Rue (1916, 

1925) and one by Follansbee (1929). 

You may be interested in brief accounts of the geology 

of other national parks and monuments, or other areas of 

special interest, such as the reports on the Uinta Mountains by Hansen (1969), Mount Rainier by Crandell 

104 
( 1969) , Yellowstone National Park by Keefer ( 1971) , 

and ones by me on Colorado National Monument (Lohman, 1965) and Canyonlands National Park (1974). 

For those who wish to learn more about the science 

of geology, I suggest the textbook by Gilluly, Waters, and 

Woodford (1968). 

,L\cknowledgments 

3 AM GREATLY INDEBTED to Bates Wilson, former 

Superintendent, and to former Assistant Superintendent 

Joe Carithers, for their splendid cooperation in supplying 

data and information; to Chuck Budge, former Chief 

Ranger; Dave May, Assistant Chief of Interpretation and 

Resource Management; Joe Miller, former Maintenance 

Engineer; Bob Kerr, new Superintendent; Maxine Newell, 

Park Historian and member of the staff at Arches National Park; Jerry Banta, former Park Ranger at Arches; 

and Carl Mikesell, Park Ranger at Arches, for their many 

favors. 

I am grateful to several colleagues and friends for the 

loan of photographs, for geologic help and data, and for 

reviewing this report. I am also deeply grateful to my 

wife, Ruth, for accompanying me on all the fieldwork 

and for her help and encouragement. 

Selected References 

Abbey, Edward, 1971, Desert solitaire, a season in the wilderness: 

New York, Ballantine Books, 303 p. 

Baker, A. A., 1933, Geology and oil possibilities of the Moab 

district, Grand and San Juan Counties, Utah: U.S. Geol. 

Survey Bull. 841, 95 p. 

Baker, Pearl, 1971, The Wild Bunch at Robbers Roost: New 

York, Aberlard-Schuman, 224 p. 

Beckwith, Frank, 1934, A group of petroglyphs near Moab, Utah: 

Santa Fe, N. Mex., El Palacio, v. 36, p. 177-178. 

Breed, Jack, 1947, Utah's arches of stone: Natl. Geog. Mag., p. 

173-192, August. 

Case, J. E., and Joesting, H. R., 1972, Regional geophysical investigations in the central Colorado Plateau: U.S. Geol. 

Survey Prof. Paper 736, 34 p. 

105 
Cater, F. W., 1970, Geology of the salt anticline region in southwestern Colorado: U.S. Geol. Survey Prof. Paper 637, 80 p. 

___ 1972, Salt anticlines within the Paradox Basin, in Geologic atlas of the Rocky Mountain region, United States of 

America: Denver, Colo., Rocky Mtn. Assoc. of Geologists, 

p. 137, 138, fig. 4. 

Cleland, H. F., 1910, North American natural bridges, with a 

discussion of their origins: Geol. Soc. America Bull., v. 21, p. 

313-338. 

Crandell, D. R., 1969, The geologic story of Mt. Rainier: U.S. 

Geol. Survey Bull. 1292, 43 p. 

Dane, C. H., 1935, Geology of the Salt Valley anticline and 

adjacent areas, Grand County, Utah: U.S. Geol. Survey Bull. 

863, 184 p. 

Dellenbaugh, F. S., 1902, The romance of the Colorado River: 

New York, G. P. Putnam's Sons, 399 p. [reprinted 1962 by 

Rio Grande Press, Chicago, Ill.] 

Everhart, W. C., 1972, The National Park Service, Praeger Library of U.S. Government Departments and Agencies No. 

13: New York, Praeger Publishers, p. i-xii, 1-276. 

Follansbee, Robert, 1929, Upper Colorado River and its utilization: U.S. Geol. Survey Water-Supply Paper 617, 394 p. 

Gilluly, James, Waters, A. C., and Woodford, A. 0., 1968, Principles of geology [3d ed.]: San Francisco, W. R. Freeman & 

Co., 685 p. 

Hansen, W. R., 1969, The geologic story of the Uinta Mountains 

[with graphics by John R. Stacy]: U.S. Geol. Survey Bull. 

1291, 144 p. 

Herron, W. R., 1917, Profile surveys in the Colorado River Basin 

in Wyoming, Utah, Colorado, and New Mexico: U.S. Geol. 

Survey Water-Supply Paper 396, 6 p., 43 pis. 

Hite, R. J ., 1972, Pennsylvanian rocks, in Geologic atlas of the 

Rocky Mountain region, United States of America: Denver, 

Colo., Rocky Mtn. Assoc. of Geologists, p. 133-137. 

Hite, R. J., and Lohman, S. W., 1973, Geologic appraisal of 

Paradox basin salt deposits for waste emplacement: U.S. 

Geol. Survey open-file report, 75 p. 

Hunt, Alice, 1956, Archeology of southeastern Utah, in Geology 

and economic deposits of east-central Utah: Salt Lake City, 

Intermountain Assoc. of Petroleum Geologists, 7th Ann. Field 

Conf., p. 13-18. 

Hunt, C. B., 1956, Cenozoic geology of the Colorado Plateau: 

U.S. Geol. Survey Prof. Paper 279, 99 p. 

___ 1969, Geologic history of the Colorado River, in The 

Colorado River region and John Wesley Powell: U.S. Geol. 

Survey Prof. Paper 669, p. I-IV, 59-130. 

106 
Jennings, J. D., 1970, Canyonlands-Aborigines: Naturalist, v. 21, 

Summer, Special Issue no. 2, p. 10-15. 

Joesting, H. R., Case, J. E., and Plouff, Donald, 1966, Regional 

geophysical investigations of the Moab-Needles area, Utah: 

U.S. Geol. Survey Prof. Paper 516-C, 21 p. 

Keefer, W. R., 1971, The geologic story of Yellowstone National 

Park, illustrated by John R. Stacy: U.S. Geol. Survey Bull. 

1347, 92 p. [1972]. 

Lansford, Henry, 1972, Boatman in the desert, a passenger-carrying sternwheeler in canyon country: "Empire" [magazine of 

the Denver Post], Nov. 5, p. 18, 19. 

La Rue, E. C., 1916, Colorado River and its utilization: U.S. Geol. 

Survey Water-Supply Paper 395, 231 p. 

___ 1925, Water power and flood control of Colorado River 

below Green River, Utah, with a foreword by Hubert Work, 

Secretary of the Interior, p. 1-100. [Appendix A, A report on 

water supply, by E. C. La Rue and G. F. Holbrook, p. 101-

123; and Appendix B, A geologic report on the inner gorge 

of the Grand Canyon of Colorado River, by R. C. Moore, 

p. 125-171]: U.S. Geol. Survey Water-Supply Paper 556, 

176 p. 

Lohman, S. W., 1965, The geologic story of Colorado National 

Monument [with graphics by John R. Stacy] : Fruita, Colo., 

Colorado and Black Canyon Natural History Assoc., 56 p. 

---1974, The geologic story of Canyonlands National Park, 

with graphics by John R. Stacy: U.S. Geol. Survey Bull. 

1327, 126 p. 

McKnight, E. T., 1940, Geology of area between Green and 

Colorado Rivers, Grand and San Juan Counties, Utah: U.S. 

Geol. Survey Bull. 908, 147 p. 

Ouellette, C. M., 1958, Over the top of Landscape Arch: Desert 

Mag., p. 13-16, March. 

Pierson, Lloyd, 1960, Arches National Monument, in Geology 

of the Paradox basin fold and fault belt: Durango, Colo., 

Four Corners Geol. Soc. Guidebook, 3d Ann. Field Conf., 

p. 17-21. 

Schaafsma, Polly, 1971, Rock art of Utah: Cambridge, Mass., 

Harvard Univ., Papers of the Peabody Museum of Archaeology and Ethnology, v. 65, 169 p. 

Stacy, J. R., 1962, Shortcut method for the preparation of shadedrelief illustrations, in Short papers in geology, hydrology, and 

topography 1962: U.S. Geol. Survey Prof. Paper 450-D, p. 

D164-D165. 

Stokes, W. L., 1952, Uranium-vanadium deposits of the Thompsons area, Grand County, Utah, with emphasis on the origin 

of carnotite ores: Utah Geol. and Mineralogical Survey Bull. 

46, 51 p., December. 

107 
___ 1970, Canyonlands- Geology: Naturalist, v. 21, Summer, Special Issue no. 2, p. 3-9. 

Walters, H. H., 1956, Pacific Northwest Pipeline- The scenic 

inch, in Geology and economic deposits of east-central Utah: 

Salt Lake City, Intermountain Assoc. of Petroleum Geologists, p. 169-170. 

Williams, P. L., 1964, Geology, structure, and uranium deposits 

of the Moab quadrangle, Colorado and Utah: U.S. Geol. 

Survey Misc. Geol. Inv. Map I- 360. 

Wilson, B. E., 1956, Arches National Monument, in Geology and 

economic deposits of east-central Utah: Salt Lake City, Intermountain Assoc. of Petroleum Geologists, 7th Ann. Field 

Conf., p. 50-51. 

Wright, J. C., Shawe, D. R., and Lohman, S. W., 1962, Definition 

of members of the Jurassic Entrada Sandstone in east-central 

Utah and west-central Colorado: Bull. Am. Assoc. Petroleum 

Geologists, v. 46, no. 11, p. 2057-2070. 

108 
[Italic page numbers indicate major references] 

A 

Abajo Mountains------------------------------···· 

artifacts .. ------------······· 

Abbey, Edward 

Page 

101 

9 

3 

Aborigines, occupation of area.. 9 

Acknowledgments....... --------------·--------- 105 

Anasazi people, petroglyphs______ 10 

Anasazi ruins ....................... ................. 9, 103 

Ancestral Colorado River.... 33 

Anomalies, gravity, Salt Valley________ 32 

Anticlines, salt -----·--···--········ 31 

Arches, broken remains........................ 44 

examples.------------················--··-- 46 

former abutments.......................... 68 

horizontal.... ---------·····-········--····----·· 44 

how they are formed.................... 42 

natural, defined.............................. 40 

number in the park. ..................... 40, 41 

origin and development.............. 37 

pothole.......... 44 

verticaL .......................................... 42, 44 

Artifacts, La Sal and Abajo Mountains.................................. 9 

Aspinall, Wayne, Representative 8 

B 

"Baby Arch" .. ------------······· ----··· 46, 63, 83 

Balanced Rock .... -··········-·---··········· 69, 70, 74 

Banta, Jerry.................. 105 

Bar-DX Ranch ................................ 12, 13, 14 

"Barrier Canyon style". -------·······-··--· 10 

Bedding, wavy, Dewey Bridge Member...... 46 

Beeson, Stib____________ 13 

Beginning of a monument.. .. 

Bending of rocks.................. 24 

Bennett, Wallace F., Senator............ 8 

Beroni, Pete ............................................ 14, 15 

Black Canyon of the Gunnison National Monument............ 102 

Book Cliffs 100 

Breaking of rocks................ 24 

Bridge, natural, defined... 40 

Broken Arch ........................... ----·-·······--· 46, 79 

Brown-Stanton expedition, exploration 15 

Bryce Canyon National Park...... 103 

Budge, Chuck --------·-·········-· 105 

c 

Cache Valley 

Cache Valley anticline .. 

---· 56, 73, 77 

25, 

32, 34, 55, 100, 101 

Cache Valley graben .......................... 34, 100 

Page 

Campground .... -----------......... 86 

water supply.... 87 

Cane Creek anticline........ ................... 24 

Canyon de Chelly National Monument....... _ -------------·--·--· 102 

Canyon King.......................................... 8 

Canyon Lands Section, Colorado 

Plateau......................... 9, 22 

Canyonlands National Park. ... 3, 9, 15, 102 

Canyonlands Natural History Association.......... 8 

Capitol Reef National Park........ 103 

Carithers, Joe ....................... . 105 

Carmel Formation............. 100 

Cassidy, Butch................................. 12 

Caves, Entrada Sandstone.......... 9 

Cedar Breaks National Monument 103 

Cedar Mesa Sandstone Member, Cutler Formation ................ 22, 102 

Chinle Formation ................ 32, 100, 102, 103 

"Cisco Cutoff". ......................... 16 

Civilian Conservation Corps.............. 2 

Cliff dwellers.... -----·------------· 9 

Climate, desert.... . ............................ 35, 51 

wetter, different landscape produced...... ...................... 37 

Collapse, salt anticlines ........................ 33, 34 

Color photographs, equipment used.. 8 

Colorado National Monument............ 102 

Colorado Plateau, geologic formations included 101 

rock formations .......... --------------- 103, 104 

subdivisions ...... ............. 18 

uranium-vanadium mining.. 14 

Colorado Plateaus Province.......... 18 

Colorado Riv&r, course established.. 101 

nighttime illuminated float trip .. 16, 52 

Colorado River canyon.. -·------- 35, 51, 52 

Cores, salt... ....... ----------·-----·--· 100 

Corral mine.. 15 

Courthouse syncline 25, 

30, 31, 32, 52, 63, 68, 100 

Courthouse Towers area.... ---·--·--· 25, 63 

number of arches ..................... 41 

Courthouse Wash _____ 2, 3, 18, 35, 63 

Cove Arch.......... -------------------- 70 

Cove of Caves 70 

Crossbedding, Navajo Sandstone 63, 

66, 70 

Cutler Formation......... __________ 32, 102 

Cedar Mesa Sandstone Member 22 

White Rim Sandstone Member.. 22 

109 
D Page 

Dark AngeL........ ................................... 92 

De Chelly Sandstone Member, Cutler Formation.... 102 

Dead Horse Point.................................. 33 

Dedication of the park........................ 8 

Delicate Arch ..................... 16, 25, 74, 75, 77 

Delicate Arch area, number of 

arches.............. 41 

Density, average, Paradox Member.. 32 

Deposition of rock materials, environments-----·····---~----·-····- 20 

Desert varnish. .................... 10 

Development of the arches................ 37 

Devils Garden ................. 2, 5, 25, 79, 83, 86 

fins...... .................... 42 

number of arches.... ....................... 41 

trail..... . ...................................... 88, 92 

Dewey Bridge.......................................... 52 

Dewey Bridge Member ........................ 46, 63 

Entrada Sandstone, composition 41 

"hoodoos and goblins"........ 66 

park road cutting.................. 57 

The Windows section............ 71 

vertical arches........................ 44 

"Dewey Road"..................................... 16 

Diapir...... .................. 83 

Differential erosion .... ----·--···········--·-····- 42 

Dinosaur National Monument ........ 101, 102 

Dissimilarity of Arches vs. Canyonlands.... . .......... 23, 24 

Double Arch ........................................ 2, 46, 72 

Double 0 Arch ................................ 90, 92, 98 

Drainage, Arches National Park........ 18 

Dry Mesa....... ..................... ................... 5, 56 

E 

Eagle Park.. . ........... 25, 98 

number of arches.......................... 41 

Early dwellers.... .................................... 9 

Earthquake, rock offset along bedding plane........................ 63 

Egyptian queen, arch resembling...... 63 

Eisenhower, Dwight D., Mission 66 4 

Elephant Butte.. ................................... 72 

Elephant Butte folds............................ 68 

Elizondo, Emmett.................................. 13 

Entrada Sandstone ................ 23, 74, 102, 103 

arches, modes of origin................ 42 

caves ..... . 

cut by normal fault .... . 

Moab Member .................. . 

no water found ............................. . 

Environments of deposition 

Erosion ....... . 

Colorado Plateau ........ 

Evaporation basins 

Evaporites ........... . 

Eye of The Whale .............................. .. 

F 

9 

57 

24 

87 

20 

99 

33 

99 

30 

69 

Facies changes............... ........................ 22 

"Father of the monument," J. W. 

Williams...... ................... 1, 4 

Faults, Cache Valley anticline.......... 34 

110 

Faults- Continued Page 

Salt Valley anticline......... 34 

Fiery Furnace ..................... 25, 42, 73, 79,83 

number of arches............................ 41 

Fins ........................................................... 63, 79 

Float trip, nighttime illuminated, 

down Colorado River.... 52 

Folds ................................................ 24, 30, 100 

Four-wheel-drive vehicles.................... 69 

Fractures................... .............. ............... 24 

Fremont people, occupation of area 9 

pictographs...................................... 10 

Frost, prying action.......... 42 

G 

Garden of Eden.... . ................... 50, 69, 70 

Gas exploration, deep tests ................ 15, 99 

Geographic setting................................. 18 

Geologic age of rocks in park............ 98 

Geologic events forming the Colorado Plateau.................... 98 

Geologic history, summary................ 98 

Geologic Time Spiral... ................... 101, 103 

Geology, at the park entrance............ 57 

Glen Canyon Group ................. 52, 102, 103 

Glen Canyon National Recreation 

Area .............................. 101, 103 

Goblin Valley State Park ................ 66, 103 

Gould, Lawrence M.............................. 1 

Goulding, Harry, first person to 

drive into The Windows 

section............................... 2, 69 

Grabens ......................................... 34 

Grand Canyon National Park and 

National Monument...... 102 

Gravity anomalies, Salt Valley........ 32 

Green River............................................ 103 

Ground water.......................................... 41 

"Guide to an Auto Tour of Arches 

National Park," (The) 5, 

50, 51, 72 

Gulf of California....... 33 

H, I 

Hastier, (Mrs.) Hazel Wolfe............ 13 

Headquarters area................................. 57 

Henry Mountains.................................. 101 

Herdina Park .......................................... 25, 69 

number of arches.......................... 41 

Hermosa Formation, Paradox Member ................. 23, 25, 29, 30, 32 

History, early........................................ 9 

geologic, summary........................ 98 

"Hoodoos and goblins" .................... 66, 103 

Hoover, Herbert, proclamation.......... 1 

Horizontal arches.................................. 44 

Horseshoe Canyon, pictographs........ 10 

Horseshoe Canyon Detached Unit of 

Canyonlands.................... 23 

Humid regions, subdued rounded 

landforms......................... 37 

Igneous rocks .......................................... 22, 99 

"Indian-Head Arch"............................ 98 

Iron in the rocks.................................. 23 

Island in the Sky.................................. 102 
J, K Page 

Jeep traiL. .............................................. 69, 70 

Johnson, Lyndon B., proclamation.. 2 

Joints ............................................... 24, 34, 100 

Kayenta Formation .............. 35, 52, 102, 103 

Kerr, Bob.... ................... 105 

Klondike Bluffs.......... 25, 69, 82, 83 

number of arches 41 

L 

La Sal Mountains .................. 22, 63, 77, 101 

artifacts............................................ 9 

Lake Mead.............................................. 33 

Lake PowelL.......................................... 33 

Land forms, formation in the park.. 33 

Landscape Arch ............................... 16, 77, 88 

second known ascent.................... 90 

Larson, Tomnty.................... ................. 13 

Lloyd, Sherman P., Representative.. 8 

Lohman, (Mrs.) Ruth............ 105 

M 

Mahan, Russel L.................................. 2 

Mancos Shale ........................................ 32, 100 

Maxwell, Ross A., investigation of 

caves................................. 9, 10 

May, David .......................................... 40, 105 

Melich, Mitchell, Solicitor General.. 8 

Mesaverde Group ................................ 32, 103 

Mesaverde National Park.................... 103 

Metamorphic rocks ................................ 22, 99 

Metric unit conversion factors.......... 2 

Mikesell, CarL...................................... 105 

Miller, Joe.............................................. 105 

Mission 66, presidential and congressional support................. 4 

Mississippi River sternwheeler 

replica.............................. 8 

Moab, uranium-vanadium mill.......... 14 

Moab bridge................ ... ....................... 52 

Moab Canyon .......................................... 15, 18 

Moab fault .............................................. 26, 57 

Moab Lions Club.................................. 1, 8 

"Moab Mail Road".............................. 16 

Moab Member, Entrada Sandstone .. 24, 35 

Entrada Sandstone, Broken Arch 46 

composition............................ 41 

"Moab panel"........................................ 10 

Moab-Spanish Valley anticline.......... 26 

Moab Valley............................................ 57 

Moab Valley-Seven Mile anticline 100, 101 

Moenkopi Formation .................. 32, 102, 103 

Monoliths.... ... .. .... ... .. .. . .. ... ... ........ ....... .. 63 

Monument, beginning................. 1 

Monument Valley .............................. 101, 102 

Morrison Formation ............................ 32, 101 

Morton, Rogers C. B., Secretary of 

the Interior 8 

Moss, Frank E., Senator.................... 8 

Moss Back Member, Chinle Formation ........................ . 15 

N 

National Park Service ........ 8, 12, 40, 75, 90 

Page 

Natural Bridges National Monument 3, 

37, 40, 102 

Navajo Arch........................................... 90 

Navajo Sandstone . 24, 35, 52, 103 

canyon floor.......... 63 

crossbedding.......... . ......... 63, 66, 70 

park road cutting...... 57 

water supply............ . .......... 57, 87 

Navajo Tribe.......................................... 102 

Needles section, The, Canyonlands 

National Park ............... 16, 102 

Newell, (Mrs.) Maxine ...................... 12, 105 

Nixon, Richard M., Congressional 

Bill.................................... 5 

North Window .................................. 40, 68, 71 

0 

Oil exploration.. .................... 15 

Cane Creek anticline.................... 24 

deep tests......................................... 99 

Origin of the arches.............................. 37 

p 

Pacific Northwest Pipeline.................. 15 

Painted Desert........................................ 102 

Panorama Point.................................... 73 

Parade of Elephants.... ......................... 72 

Paradox basin........................................ 23 

Paradox Member, Hermosa Formation ......... 23, 25, 29, 30, 82, 99 

Hermosa Formation, average 

density.............................. 32 

upward intrusion.................... 34 

Park, a trip through............................ 52 

dedication........................................ 8 

how to see........................................ 50 

improvements .................. ---············ 4 

Park Avenue, trail................................ 63 

Park Service. See National Park 

Service. 

Partition Arch........................................ 90 

Petrified dunes ........................................ 63, 66 

Petrified Forest National Park.......... 102 

Petroglyphs, Ute .................................... 10, 75 

Pictographs, Fremont people.............. 10 

Pine Tree Arch................ 90 

Pinon pines................ 86 

Pipeline scars, Pacific Northwest 

Pipeline............. 15 

Plateau, uplift and erosion................ 33 

Potash occurrence........... ...................... 15 

Pothole Arch................. . .......... 50, 73 

Pothole arches . 44 

Powell, John Wesley, Canyonlands 

National Park................. 15 

Professor Valley............................. 56 

R 

Rainbow Bridge National Monument 103 

Rainwater.......... . ...................... 41, 42 

Rampton, Calvin L., Utah Governor 8 

Reading, additional.............................. 104 

References, selected....... ...................... 105 

111 
Page 

Relief map, shaded, Arches National 

Park, described .............. 18, 19 

Ribbon Arch.......................... 72 

Richardson Amphitheater.................... 56 

Richardson, Professor. 56 

Rico Formation.... ................... 23 

Rison, (Mrs.) Esther Stanley 13 

Rock formations, sculptured by erosion..... 35 

Rock openings, natural, types......... 37 

Rock types in the park 35 

Roosevelt, Franklin D., proclamation ................... 2 

Rumel, Hal, photographer...... 77 

"Run, Cougar, Run" ................... 16, 56, 75 

s 

Sagers Wash syncline 86 

Salt, occurrence ........... . 15 

properties critical to formation 

of salt anticlines............ 30 

Salt anticlines ............................... 30, 31, 100 

collapse........ . ............ 33, 34 

Salt-bearing rock....................... . .. ... 83 

Salt rolls................................ 31 

Salt Valley .............. 2, 68, 73, 77, 82, 83, 92 

gravity anomalies.......................... 32 

Salt Valley anticline............................ 25, 

collapse ....... . 

30,31,32, 73,100,101 

34 

42 

................ 3, 74, 82, 83 

fins 

Salt Valley Wash .... 

Salt Wash ····················· 35, 55 

Anasazi ruins .. ---······---·--······----- 9 

drainage..... ...................... 18 

grabens............................. 34 

sandstone caves near.................... 10 

Salt Wash Sandstone Member, Morrison Formation.............. 14 

San Juan Basin, natural gas... 15 

San Rafael SwelL ......... 101, 103 

Sand Dune Arch................ 79 

Sandstone fins.................... . ....... 41, 42 

Schaafsma, Polly, quoted ......... 10, 12 

Scenic drive, Moab to Cisco.............. 16 

"Scenic Inch," Pacific Northwest 

Pipeline.... 15 

Sedimentary rocks.................. 20 

modes of deposition...................... 99 

Seven Mile-Moab Valley anticline.... 26, 

Sevenmile Canynn ................................ . 

32, 57 

15 

63 

83 

Sheep Rock. .......................... . 

Skyline Arch ............................ . 

Slick Rock Member, Entrada Sandstone ......... . 34 

Entrada Sandstone, composition 41 

112 

high fins and pinnacles 63, 79, 86 

hiking trail between fins...... 90 

park road cutting....... 57 

salmon....... 77 

The Windows section ... 

Tunnel Arch ...... . 

vertical arches .... . 

71 

46 

.... 42, 44 

Page 

Slumping of sediments, irregular...... 50 

Snow ......................................................... 41,51 

Sonic booms, dangers posed to 

arches ............................... 16, 17 

South Window .................................. 40, 68, 71 

Spanish explorers.................................. 12 

introduction of horses to this 

country........... 10 

Squaw Flat Campground.................... 16 

Stanley, Esther....................................... 13 

(Mrs.) Flora................................. 13 

Volna.... ........................................... 13 

Stevens, Dale J........... . 40, 41, 63, 90, 98 

Strata, lateral changes across the 

park............................. 22 

Sundance Kid...... 12 

Sunset Crater National Monument.. 103 

Supersonic flights banned, MoabTimes Independent........ 17 

Suspension bridge, Colorado River.... 16 

T 

Tanner, (Mrs.) Faun McConkie...... 1 

Taylor, L. L. (Bish). 1 

Temperatures.... ....................... 51 

"The Guide to an Auto Tour of 

Arches National Park" 5, 

50, 51,72 

The Needles section, Canyonlands 

National Park. .............. 16, 102 

The Windows section............................ 25, 

41, 46, 51, 66, 68, 69, 70 

Three Gossips.... 63 

Three Penguins...................................... 57 

Tower Arch ................... ·-························ 83 

Tunnel Arch ..................................... 40, 46, 90 

Turnbow, Marv................................ 1 

Turnbow cabin........................... 13 

Turret Arch .......................................... 68, 71 

u,v 

Uncompahgre Highland ............. 23, 99, 100 

Uncompahgre Plateau .......................... 23, 99 

Uplift, Colorado Plateau.................... 33 

Upper Devils Garden.......................... 98 

number of arches.......................... 41 

Uranium mines.............................. 14 

Ute petroglyphs ...................................... 10, 75 

Vanadium mines.................................... 14 

Vegetation.............................................. 37 

Vertical arches ........................................ 42, 44 

Visitor Center ............................ 50, 51, 57, 86 

Volz, J. Leonard ............................ 8 

w 

Walker, Lester .................... . 

Wall Arch .............................................. . 

Walt Disney crew, "Run, Cougar, 

Run''---··············-···-······----

Wasatch Formation .................. . 

Water supply, Navajo Sandstone ..... . 

to the campground ....................... . 

13 

90 

75 

32 

57 

87 
Page 

White Rim Sandstone Member, Cutler Formation.. 22 

Wild Bunch, The·----------------------··--·-····· 12 

Williams, J. W ... ---------------·--···--·--·--·-··-· 1, 4 

Wilson, Bates...... ------·---·-·····--··-· 1, 3, 105 

Wilson, (Mrs.) Bates ......... _ 3 

Windows, distinguished from arches 40 

Windows section, The.................... 25, 

46, 51, 66, 68, 69, 70 

number of arches............................ 41 

Wingate Sandstone ............... 35, 87, 102, 103 

Wirth, Conrad L.................. 4 

Page 

Wupatki National Monument____________ 102 

Wolfe cabin __ .......................... 1, 3, 12, 13, 14 

Wolfe, Fred ____ ...................................... 12, 13 

Wolfe, John Wesley __________ ................... 12, 13 

Wolfe's Bar-DX Ranch ..... 9, 10, 14, 74, 75 

Y, Z 

Yellow Cat area (Thompson's area) 14 

Yellow Cat Flat...................................... 86 

Yellow Cat mining district.................. 83 

Zion National Park............................. 103 

ti U.S. GOVERNMENT PRINTING OFFICE, 1975-679-138 

113