Geological Survey Bulletin 612 Guidebook of the Western United States: Part B

SHEET No. 15B. (click on image for an enlargement in a new window)

The main highway from Utah to Montana follows the foot of the mountains on the west side of Cache Valley to its very head. Along this road are several old Mormon settlements, among which is Dayton (see sheet 15B, p. 124), located at the mouth of Dayton Canyon and the junction of a very rough road leading over the mountains to Malade. The big cliff at the mouth of Dayton Canyon is composed of very ancient sedimentary rocks (Cambrian?) dipping westward at a low angle. About half a mile up the canyon these rocks have been overridden by much younger (Carboniferous?) limestone, showing that the mountains west of this end of Cache Valley were formed by the piling up of upturned broken slabs of the earth's crust. The foothills back of Dayton are made of sandy and limy rocks which were originally deposited as sand and mud in a fresh-water Tertiary lake. Such rocks are found in many places around the edge of Cache Valley.

The train now approaches on the east a north-south ridge several hundred feet high, known as Battle Creek Butte. It is isolated in the midst of the valley and takes its name from Battle Creek, the scene of an Indian fight near its eastern base. Much of the ridge is made up of very old shales (hardened mud rocks), but the south end and some of the top are composed of diorite, a kind of granite which, in a molten condition, was forced up into these shales from below. This molten rock may not have reached the surface, for the surface at the time of the intrusion was considerably above the present one. Whether this ridge is an uplifted fault block or a remnant left by the forces of erosion has not been determined, but it certainly was an island when Lake Bonneville stood at its highest level. The north end of the ridge consists of soft Tertiary sandstone.

Opposite the middle of Battle Creek Butte is Garner, a station for the village of Clifton, which lies at the edge of the flat 1 mile west. Clifton is an old Mormon hamlet of about 100 people. Late in the afternoon the mountains on the west appear a hazy blue, details are obscured, and it may not be possible to distinguish the low rounded foothills made by Tertiary conglomerate and sandstone or to see the prominent lake-cut benches which continue along the edge of the valley as far north as Oxford.

A large reservoir among the Tertiary ridges just east of Garner is filled from a ditch that brings water from Mink Creek, several miles to the northeast. An inverted siphon carries water from this reservoir across the creek at Garner, and a wooden pipe line that goes under the railroad at the first road north of Garner station takes the water to Clifton, where it is turned into irrigation ditches. About 31,000 acres is irrigated from this one system.

A short distance north of Garner a clear view is again obtained of the Bear River Range, several miles to the east (right), and of the low Tertiary hills in front of it. The railroad passes a big marsh, one of the few areas in this part of the valley which is not yet much utilized, and continuing along the practically level lake floor comes to the station for a Mormon village, Oxford, which stands among the trees 2 miles to the west. The Provo shore line may be seen near the village. If Cache Valley should be filled again to the highest level of Lake Bonneville, Oxford village would be 400 feet under water, and the temple at Logan would stand in water 500 feet deep.

A low ridge just north of Oxford station extends eastward from the mountains and makes the valley bottom much narrower. Directly ahead, about 7 miles distant, there are two prominent rocky points, which mark Red Rock Pass, the old outlet of Lake Bonneville. West of the track is Swan Lake, a small body of water on which it is common to see many ducks either resting quietly or, frightened by the train, skittering away through the weeds. The railroad grade, which has been gradually rising to Swan Lake station, now begins to descend. By the overflow of Lake Bonneville the drainage divide was moved from Red Rock Pass, where it stood before Bonneville time, back to this point, nearly 7 miles farther south. Sand and gravel dumped by small creeks coming out from the hills have dammed this part of the valley, making a marsh which extends most of the way from Swan Lake to the pass. The hills on the east are composed of Tertiary sediments, mostly shale, and show the Bonneville shore line about 340 feet above the marsh. At Red Rock Pass red limestone cliffs appear on both sides (Pl. XXXI, p. 113). From the road crossing just south of the pass may be seen on the right a small valley coming down from the northeast. This is the head of Marsh Creek, which in pre-Bonneville time probably drained southward into Bear River, but which, by the shift of the divide just mentioned, now turns at a sharp angle and goes through the pass to join the Snake River drainage system. Through this valley went the magnificent river made by the overflow of Lake Bonneville.

PLATE XXXI.—RED ROCK PASS AND THE OUTLET CHANNEL OF LAKE BONNEVILLE.

As most of the water of Marsh Creek is used in irrigation, the natural channel through the pass and for a short distance north of it may be dry in summer. The knobs of limestone, 200 to 300 feet high, which overlook the channel from opposite sides leave a maximum width of 600 feet for the river that drained Lake Bonneville just before it was drawn down to the Provo stage. (See Pl. XXXI.) When Lake Bonneville first started to overflow, the lake level stood higher than the tops of these limestone rocks, which had been buried beneath mountain waste. Gravel deposited by the stream that drained the lake at its highest stage is found on top of the red butte along the base of which the train passes. The Hunt ranch, mentioned by Gilbert in his description of this old outlet of Lake Bonneville published in 1890, was at the foot of this rocky citadel. The limestone crags bordering Red Rock Pass are conspicuous features of the landscape and were well known to the early travelers in this region and to the freighters who hauled supplies for the western Montana mining camps over the road that follows the course now taken by the railroad. The traveler going north from the pass may notice that although the steep-sided valley is a quarter of a mile or more wide, its stream is only a rivulet meandering through the meadow. (See Pl. XXXI.) The ill-matched stream and valley afford evidence that a great river once flowed where now there is only a brook. (See pp. 97-98.) Here, then, at or just north of the red cliffs, Lake Bonneville overflowed its rim and began the discharge which continued until evaporation exceeded inflow.

The valley bottom becomes wider toward the north, and the train leaves it and comes out upon a broad bench, from which an extensive view may be had of the valley of Marsh Creek.¹ On this bench is Downey, a small settlement in the midst of an extensive agricultural district. The first homes were built here about 1894, but it was not until 1910, when water was brought by a large irrigation canal from Portneuf River below Lava Hot Springs and it became possible to irrigate the land, that the settlement had any marked growth. It was named for one of the engineers or officers of the Oregon Short Line. The grain elevator and the broad fields of grain that stretch away in all directions tell of the principal industry of the people. About 12,000 acres is irrigated by the Downey Improvement Co.'s ditch and cultivated. When the ditch was completed in 1910 land sold for $35.50 an acre, $35 for the water right and 50 cents for the land. In 1914 it was worth about $45 an acre with water right but without improvements.

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¹Marsh Valley, like Cache Valley, is inclosed between mountain ranges, and has a north and south trend. Its length is about 35 miles, and its greatest width is 8 or 10 miles. Twenty miles from Red Rock Pass the Portneuf River breaks through the eastern mountain chain and enters the valley, turning northward and running parallel with Marsh Creek to the end of the valley. There it receives the creek and then turns abruptly westward and escapes from the valley through a deep but open canyon. The upper canyon of the Portneuf has at some time admitted lava as well as water. A succession of basaltic coulees have poured through it into Marsh Valley and have followed the slope of the valley to the lower canyon. The Portneuf River follows the eastern margin of the lava beds, and Marsh Creek the western, each occupying a narrow valley sunk from 30 to 100 feet below the level of the lava table. A comparison of these valleys illustrates the disparity between Marsh Creek and its channel. Portneuf River is several times larger than Marsh Creek, but the immediate valley by which it is contained is smaller. Indeed, there is every evidence that the valley of Marsh Creek, having been formed by the ancient Bonneville River, is now in process of filling. It abounds in meadows and marshes and at one point contains a lakelet.

It appears, however, that the Bonneville River was not contained during its entire existence in the channel now occupied by Marsh Creek. The whole upper surface of the lava tongue, where it has a width of more than a mile, is fluted and polished and pitted with potholes after the manner of a river bed, and there seems no escape from the conclusion that it was swept by a broad and rapid current.

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Oxford Peak (elevation 9,386 feet), which overlooks Red Rock Pass, appears from Downey as a mountain mass with two tops of about equal height. The front of the mountain range east of Downey is made up of Carboniferous limestone dipping to the east; the mountains on the west are composed of Ordovician rocks, also dipping east. In all directions there is a strong suggestion that the comparatively level valley floor between the two mountain ranges was produced by outwash from the mountains. In other words, the débris brought down from the surrounding mountains by the numerous streams has spread out as a great apron, filling the valley to a considerable depth, and every year, especially at times when the streams are high, a little more sand and gravel are added to the deposit. The valley of old Bonneville River, now occupied by Marsh Creek, is cut in this fill. At Downey the flat floor is composed, at least near the surface, of well-rounded sand and partly cemented gravel. It is said that a well 600 feet deep west of Downey was drilled entirely in hill wash.

Virginia is the station for a considerable number of farmers living on irrigated lands in the vicinity. The fine large school buildings here and at Arimo, a few miles farther north, are typical of the school facilities provided for country pupils in this part of Idaho. After leaving Virginia the train runs down below the level of the upper bench and at Marsh Valley siding passes gravel pits from which a great quantity of material has been taken for fills and ballast along the railroad. The gravel shows the character of the valley filling. Arimo is one of the numerous little settlements on the main highway between Ogden and Pocatello, which parallels the track for many miles.

The valley of Marsh Creek has been flooded with lava in one of the later stages of geologic history, probably in Pleistocene glacial time. Lava of this kind, a basalt, is widespread in southern Idaho. It is seen first in Marsh Creek valley about 1-1/2 miles north of Arimo, between mileposts 106 and 107. The edge of the lava first appears as a low vertical wall of black rock on the east side of the creek, just north of some ranch buildings. Marsh Creek flows along the west side of the lava and the railroad runs along the east edge for a short distance, gradually going up on the upper surface, which it traverses to McCammon. The surface appears smooth, but so much of it is bare rock partly hidden by sage-bush that the land is not cultivated. Near McCammon, where there is more soil on the lava, crops are being raised. Just before reaching McCammon the traveler can see on the east the defile which Portneuf River has cut through the mountains. In the forties and fifties pioneers from the Mississippi Valley bound for Oregon diverged from the Astor route and entered the Snake River valley through this defile by ox team, where travelers now pass along in Pullmans and Packards.

At McCammon, the junction of the Granger and Ogden branches of the Oregon Short Line, the mountains on both sides of the valley are composed of Ordovician shale, limestone, and quartzite, dipping to the east. A cross section of the valley at this point (fig. 14) shows a fold in the hard rocks which explains how a single formation may occur in the same position in two parallel mountain ranges. It also shows the relation of the mountain wash to the bedrock and contains in diagram the record of an interesting series of events. After the mountains were uplifted and had been somewhat worn down by erosion, there seems to have been a long period when the earth's crust in this region remained practically stationary and the refuse from the wearing down of the mountains on both sides gradually filled the valley to a considerable depth. Subsequently, an elevation of this region gave the streams greater fall, which increased their cutting power, so that they gradually washed out deep gullies in the fill. Then came a period of volcanic activity during which great quantities of lava welled up through cracks in the earth's crust and flowed out from volcanoes. The bottom of the valley occupied by Marsh Creek and Portneuf River, from a point near Arimo to Pocatello, was filled with black lava, most of which probably came up from a crack along the valley bottom. After the lava cooled Portneuf River, coming out from its canyon on the east, may have flowed for a time directly across the top of the lava to the west side of the valley, as suggested by an abandoned channel to be seen along the railroad just before entering McCammon, and there joined Marsh Creek. Subsequently it cut a new course along the east edge of the lava tongue to its present position and left Marsh Creek in possession of the opposite ledge. Long after the lava had cooled Lake Bonneville formed and its outlet stream through Red Rock Pass poured down Marsh Creek valley, flowed over the top of the lava, leaving deposits of sand and gravel in its wake, and carved deep channels on both sides of the narrow lava tongue.

FIGURE 14.—Cross section of Marsh Creek valley at McCammon, Idaho.

A place of more than local interest is Lava Hot Springs, in Portneuf Canyon 12 miles east of McCammon, where in 1914 the State of Idaho built a natatorium inclosing a concrete swimming pool 33 by 66 feet for public use. A number of hot springs issue from the bank of the river, and near them is a popular camping place. In the canyon at and above the hot springs there is considerable calcareous tufa, a soft cellular limestone deposited by the evaporation of water carrying lime in solution.

The gently sloping benches or terraces from McCammon to the foot of the mountains on the east and west are composed of outwash material which, though deposited by mountain torrents, has nevertheless accumulated so gradually that it makes a good soil. Large quantities of grain are raised on it by dry farming. The great white ledge seen on the mountain side 5 miles east of the village is a band of gray sandy limestone about 100 feet thick. The Harkness ranch, just north of the village, was one of the first in this region and was a common stopping point for freighters before the railroad was built. Mr. Harkness maintained a toll bridge over Portneuf River at this point.¹ Water power at McCammon runs the local gristmill and electric-light plant.

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¹Measurements of the flow of Portneuf River show a mean discharge of 265 second-feet at Topaz, a station in the canyon east of McCammon, during 1913-14 and of 334 second-feet at Pocatello during 1897-1899 and 1912-1914. The records at Pocatello show from a minimum flow of 14 to a maximum flow of 1,880 second-feet. No large power plants are feasible on this stream.

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Immediately on leaving McCammon the train runs down off the top of the lava into a little canyon, and for a number of miles follows the river and the edge of the lava. Toward the north the lava wall increases from 10 to 50 feet in height. In most places its upper edge is well exposed, but the lower part is concealed by large and small blocks broken from the ledge above by frost action and other natural forces. Fine exposures of black columnar basalt² are almost continuous on the west side of the track. Areas a few yards in extent showing radiate columnar structure may be seen at several points close to the railroad between McCammon and Pocatello.

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²Columnar structure, or the division of a rock into prisms more or less straight and parallel to one another is a common feature of basalts. Well-known examples of this structure are the Giants Causeway and Fingals Cave, in Ireland; the lavas in the Auvergne, in central France; the Palisades of the Hudson; the Watchung Mountains, west of Orange, N. J.; and the lavas in the Snake River canyon of Idaho and the valley of the Columbia in Oregon. As in the drying of a mud puddle cracks break the surface into figures having five or six sides, so in the cooling of molten basalt the prismatic shrinkage cracks start at right angles to the cooling surface. If the rock were perfectly homogeneous and the cooling uniform, the columns would all be hexagonal and of uniform thickness. The slower the mass cools and shrinks the larger will be the columns, and as the upper and lower surfaces of a mass of lava are likely to cool at different rates, it is common to find the lower portion separated into larger columns than the upper portion. As the columns are developed at a right angle to the cooling surface it follows that a sag or depression in the surface of a basalt sheet is underlain by radiate columnar structure.

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Onyx is a siding just below a concrete bridge over Portneuf River. Near milepost 200¹ the river tumbles over falls made by travertine, a soft cellular limestone deposited from calcareous spring waters. The small knobs of limestone in the valley bottom between the 198 and 200 mile posts were once buried in the lava which spread over the whole valley floor but have been brought to light again through the wearing away of the lava by the river.

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¹In the Portneuf Valley between McCammon and Pocatello the railroad mileposts indicate the distance west of Granger, Wyo.

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Near the 201-mile post the railroad and river turn to the middle of the larger valley, where there are basalt walls on both sides. An abandoned channel of Portneuf River continues along the east edge of the lava mass, so that the lava east of Inkom is an isolated block lying between the abandoned channel and the new channel of Portneuf River.

At Inkom, a small settlement just below the point where Marsh Creek enters Portneuf River, the river turns from north to west and cuts through the range in a deep, narrow valley. The basalt formerly occupying the present position of Inkom has been gradually removed by the stream which comes in from the northeast. Portneuf River has worn the basaltic lava away from the south side of the valley from Inkom to Pocatello, leaving a black columnar wall on the north side of the track. In some places it is very apparent that there are two thin sheets of lava, one resting upon the other, indicating two distinct volcanic outbursts. About 4 miles west of Inkom the lava stops short, and there is none in the narrow pass through the mountains.

The valley of Portneuf River from McCammon to Pocatello is cut in ancient Paleozoic rocks, including limestones, shales, and quartzites, tilted at various angles but for the most part to the east. The Bannock Range west of Inkom, through which the train passes so quickly, is composed of Ordovician strata which are more or less folded, an anticline or upward bend being indistinctly recognizable on the south wall of the pass. There is no picturesque canyon here—only a short, sharp gap. A great fault or break in the rocks along the west side of the range crosses the river at the west end of this gap, but no trace of it can be seen from the train.

As soon as the train leaves the gap a basalt wall is seen again on the north. Probably the lava was originally continuous through the gap, having flowed down the valley from McCammon as a great molten tongue, but if so it has been completely removed from the gap by the river. Plainly there are two lava sheets here. The columnar structure is well developed, as shown in the vertical wall at the edge of the basalt. At a few places where there were original sags in the surface of the mass radiate structure can be recognized. The basalt ends in the Portneuf Valley with a gentle slope about 3 miles east of Pocatello. Near Pocatello the mountains swing away to the west and north, making room for the city.

A low, steep-faced reddish ridge north of the track just east of the city appears to be a block of Ordovician quartzite uplifted by faulting.

Pocatello,¹ another "gateway to the mountains," is the junction of the divisions of the Oregon Short Line running north to Butte, Mont., and west to Huntington, Oreg. It was named for an Indian chief and began as a tent city in 1882, when the railroad was completed to this point. The early history of this locality is a wild one. In the days when the overland stage made its way through Portneuf Valley trouble with Indians and with highwaymen was common. The city is built on a town site of 2,000 acres sold by the Indians to the United States. It is divided by the railroad into two distinct parts, connected by a viaduct which crosses the numerous tracks at the station. It is growing rapidly and already has many noteworthy institutions, such as a Federal building, a Carnegie library, a hospital, a large railroad Y. M. C. A., and fine schools, including the Academy of Idaho, which bridges the gap between the common schools and the State university. The electric light and power used in the city is generated at American Falls, 25 miles west, on Snake River. The growth of the city is due largely to the railroad shops, which give employment to hundreds of men.

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¹The railroad mileposts from Pocatello to Idaho Falls give the distance from Ogden.

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Just west of the city highly tilted Cambrian quartzite is overlain by rhyolite, a light-colored siliceous volcanic rock, which flooded the surface before the basalt came. As the train leaves the station and passes the roundhouses and extensive railroad shops the traveler sees to the west the great Snake River plain. Far out in this plain a solitary mountain appears in dim outline. This is Big Butte, the cone of an extinct volcano, and the westernmost of three buttes which for generations have been landmarks in this part of the country.

Farther than the eye can see the Snake River plain stretches away to the west. The valley of the ancient Snake River was flooded with great outpourings of black lava, which spread out sheet on sheet, buried the old land surface, and partly filled the valley with molten rock, which solidified and has remained to this day undisturbed except for the gorges that the streams have cut in it. In some places old mountains project through the petrified lava flood as islands project above the surface of the sea, and old ridges stick out into it as capes and promontories.

The description of the Snake River plain below given¹ is taken from a report written in 1901 by I. C. Russell.

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¹Southern Idaho is a region composed of geologically old rocks, which formed an ancient land surface having a rugged relief. In the depressions of this surface, during later geologic time, extensive lake and stream deposits and vast lava flows were spread out. The older rocks, sharply separated from the younger by a long time interval, during which extensive movements in the earth's crust and deep erosion took place, are mainly granite, rhyolite, quartzite, and limestone. The younger of these is probably the limestone which is thought to be of Carboniferous age. These rocks were variously folded, faulted, and upheaved into prominent mountains, and deeply dissected by a large river, with many tributaries, which was long lived. The valley of the main stream, the ancient representative of Snake River, became broad and had many important tributary valleys opening from it and extending far into the bordering mountains. The sharp-crested mountain spurs between the lateral valleys are in some instances prolonged far into the main depression.

After the topography had passed maturity—that is, after the streams had excavated deep valleys, leaving sharp-crested or serrated divides between them—the main stream was obstructed, possibly by lava flows, but more probably by an upward movement of the rocks athwart its course, in the region now included in western Idaho and eastern Oregon, and a lake was formed which occupied a large part of the country now included in the Snake River plains. This water body, named by Lindgren Lake Payette, received the sediment brought in by tributary streams and the dust blown out by volcanoes and became deeply filled. These sediments, which have a known depth of over 1,000 feet, are now well exposed, particularly in southwestern Idaho. In places they contain impressions of leaves of trees which grew on the borders of the old lake, the shells of fresh-water mollusks, the bones of land mammals, and other remains. The fossils record a Tertiary (Miocene) age.

Before Lake Payette came to an end the vast lava flows which now form such a conspicuous feature of the Snake River basin began to be outpoured. In fact, the lava and the sediments of Lake Payette and of a later lake in the same basin were contemporaneous, the lava and lake sediments being interbedded. Some of the lava flows entered the lake, and the occurrence of thick beds of volcanic fragments (lapilli) and of scoriaceous, glassy lava, with a torn and slaglike structure, at the base of thick sheets of usually compact basalt records the energy of the steam explosions that followed. Highly liquid lava continued to be poured out at various intervals from a large number of volcanic vents and spread out in the previously formed basin, making, in truth, lakes of molten rocks. Besides these two processes of upbuilding—that is, sedimentation in lakes and the outpouring of lava which spread widely—there was a third, the washing of debris from the uplands and its deposition in alluvial cover and widely extended sheets of sand, gravel, and silt in the valleys. In addition, there are widespread eolian [wind] deposits. The volcanic eruption continued after the lakes were either filled or drained, so that by far the larger portion of the Snake River plains is directly underlain by sheets of basalt. The last of the extensive volcanic discharges happened in very recent times, and the process of stream deposition still continues.

The estimated area covered by the Snake River lava is in the neighborhood of 20,000 square miles. So far as is now definitely known, there is but one lava field in North America of greater extent, namely, the Columbia River lava, the estimated area of which is about 200,000 square miles. In Snake River canyon, below Shoshone Falls, nearly 700 feet of lava in horizontal sheets are exposed, but whether this is the maximum thickness or not can not be told. As a rule, the various sheets of lava are relatively thin, averaging perhaps 50 to 80 feet and widely extended. That many independent outflows of lava have occurred is easily seen, but in the walls of Snake River canyon, where the best sections are exposed, it is difficult to determine the number unless lacustral deposits, beds of lapilli, etc., occur between them.

Although the soil of the Snake River plains has well-marked variations, it may be said that in general, and, in fact, almost everywhere, it is fertile and needs but the requisite moisture to enable it to produce a strong growth of either native or cultivated plants. In general, however, the soil of the plains is a fine yellowish-white siltlike material, largely a dust deposit, which mantles the surface not only on level tracts, but covers hills and broad depressions alike. This material is similar to the celebrated loess of China, except that it usually occurs as a comparatively thin layer, and resembles also the deposit bearing the same name in the Mississippi Valley. Like each of these formations, it is of exceptional fertility if properly irrigated.

The ever-present and characteristic plant of the Snake River plains is the sagebrush (Artemisia tridentata), which grows abundantly and, we might say, luxuriantly in the dry soil from the bottom of the Snake River canyon up to an elevation of some 2,000 or 3,000 or more feet on the mountains bordering the plains. It covers the broad arid valleys almost completely and is seldom lacking over any extensive area except where fires have recently occurred or cultivated fields supplant it. On the plains in summer fire sometimes sweeps through the sagebrush in much the same manner that it does over the prairies and "burns" are produced. The "sage" in the localities most favorable to its growth attains a height of about 10 feet, but usually is not over 3 feet high, the clump of bushes being commonly 6 to 8 feet apart. One can ride or walk over the sagebrush plains with but little difficulty. The light grayish-green leaves of this ubiquitous plant give color, or perhaps more properly, lack of color, to the plains and enhance their monotony. Although the Snake River plains are frequently termed a desert, the name is true only in the sense that they are practically without water. Comparatively little of the surface is destitute of plant life. In fact, the flora is found to be abundant and varied if one examines it closely. There are many lovely plants that blossom early in the spring, filling the air with fragrance, and in the summer and fall the yellow of sunflowers and of the still more plentiful "rabbit brush" (Bigelovia graveolens), a relative of the goldenrod, here and there give broad dashes of brilliant color. Beneath the sagebrush in a state of nature nutritious bunch grass grows abundantly and still furnishes pasturage where sheep have not ravished the land. Where the plains are broadest—that is, north of the Oregon Short Line Railroad and especially in the vicinity of the three steptoes, Big, Middle, and East buttes—much of the land is without sagebrush and in the condition of a rolling prairie, which supplies excellent winter pasturage.

On the plains, more especially in the broader portions in the vicinity of the three prominent buttes that break their monotony, big game is still to be found. Antelope roam over them throughout the year, while deer and elk find there a safe winter range. The mountain sheep is also present in winter, and the mountain goat is reported to have been met with. The great horn cores of the mountain sheep are occasionally to be seen bleaching among the clumps of sagebushes. Occasionally also the horns and bones of the bison are found, showing that southern Idaho was within the former range of that species. Besides the animals just mentioned, the plains are visited by bears, wolves, lynxes, foxes, and skunks, and the coyote is only too abundant. Ducks, geese, and other birds visit the ponds and streams, particularly along Snake River and on the west side of the plain to the Lost River country. Grouse of several species are common and smaller birds are by no means rare.

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