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

SHEET No. 20. (click on image for an enlargement in a new window)

At Preble Humboldt River enters another canyon, which extends though the Hot Springs Range. Just east of Preble, above the upper end of the canyon, may be seen bluffs of black shale with some fractured and iron-stained limestone. West of Preble the limestone, which is exposed in railroad cuts, is in thick dark-bluish beds with veinlets of white calcite, separated by some thick layers of shale. These strata dip toward the east, and their general trend is southwest, so that the railroad crosses them. The rocks belong, at least for the most part, to the Star Peak formation, of Triassic age. Rocks of this formation make up a large part of the Humboldt and other ranges, to be passed later, though there will be no other opportunity to see them so close at hand.

Golconda, another old stage station, is a warm-spring resort and a supply point for numerous mining camps. In 1897 a smelter and a concentration mill were built at Golconda to treat the copper ores from the Adelaide mine¹ about 12 miles to the south. The ore proved difficult to treat, and the mill, in which several processes were tried, is no longer used. It stands north of the track. The Pequart mine, an early producer, is about 6 miles south of Golconda, and there is a gold mine in the lone conical hill about 2 miles south of the station. Ranches stretch along the river below Golconda. The crops raised are alfalfa, native hay, and potatoes.

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¹The Gold Run district, in which the most important mine is the Adelaide, is on the east slope of the northern part of the Sonoma Range—the Havallah Range of the Fortieth Parallel Survey reports. The district was organized in 1866.

The ore is a replacement of limestone and contains copper, zinc, and a little lead (pyrrhotite, chalcopyrite, sphalerite, and galena with garnet, pyroxene, etc.). The general country rock is dark calcareous slate (Star Peak) of Triassic age.

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The elevation of Golconda is almost exactly that of the highest level attained by Lake Lahontan,² already referred to as having spread over a large part of northwestern Nevada. The history of this great lake is analogous to that of Lake Bonneville, in Utah, already described (pp. 97-99 and fig. 10, p. 82).

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²The large lake which flooded a number of the valleys of northwestern Nevada at a very recent geologic date but has now passed away was named Lake Lahontan in honor of Baron La Hontan, one of the early explorers of the headwaters of the Mississippi. The lake covered approximately 8,400 square miles at its greatest expansion, and in its deepest part, the present site of Pyramid Lake, it was at least 880 feet deep—that is, its surface stood approximately 500 feet above the present water surface of Pyramid Lake. The ancient lake had no outlet except the one that led straight up, its waters being dissipated entirely by evaporation.

Fluctuations of the water level in these ancient lakes undoubtedly record climatic changes. It has been generally concluded that the periods of lake expansion were related to the stages of ice extension in the glacial epoch, or more specifically that their waters rose to their highest levels during the period when the glaciers were retreating from their farthest advance.

With the decrease of water supply the lake level has fallen, and in many parts of the basin the water has almost or entirely disappeared. Traces of former levels remain, however, in the form of elevated beaches. As the lake fell, ridges emerged and separated it into smaller units. Some of these minor basins are now essentially dry, although the lowest parts are periodically flooded to shallow depths during rains. When these areas dry up they show almost level floors with smooth mud surfaces, which check or crack in the dry air. These are the so-called mud lakes or playas which are in some basins very extensive. The basins that are still fed by perennial streams contain lakes.

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The Overland Route passes across the basin of Lake Lahontan at what is nearly its widest part. For 177 miles from a point in the Humboldt River valley near Golconda to a point in Truckee Canyon about 15 miles beyond Wadsworth or Fernley, the train passes over the bed of this extinct lake, and many of the features of the landscape and some of the rocks seen in the valleys along the route are evidences of its former presence. The mountain ranges stood as islands or peninsulas in this body of water, and when the eye is trained to recognize them the old shore lines can be traced from point to point along the slopes.

Between Golconda and Humboldt Lake Humboldt River flows in a trench that it has excavated in Lake Lahontan sediments since the last drying up of the ancient lake. For a number of miles below Golconda the river is practically a surface stream flowing between low banks of marly clay belonging to the upper part of the lake deposits. At Mill City its channel begins to deepen, and at Rye Patch the river is a little over 200 feet below the general level of the desert. The general appearance of the trench cut by the river in the lake sediments is shown in Plate XXXVII (p. 177). The threefold division of the strata exposed in the steep banks (upper lake clays,¹ medial gravels, and lower lake clays) is easily distinguished where the beds are not obscured by débris. Below Rye Patch the banks decrease in height, and south of Oreana they are in few places over 40 or 50 feet high. The total thickness of the section thus exposed is not much over 200 feet. Borings in the desert valleys, however, have developed the fact that sediments of similar character occupy the rock troughs between the mountain ranges, in many places to very great depths, probably thousands of feet. No way has been devised of determining how much of this filling was deposited in the Quaternary lake and how much may be older, possibly of Tertiary age.

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¹According to I. C. Russell, mammalian bones were obtained at a number of localities in the sides of the Humboldt and Walker River canyons and, with the exception of a single vertebra found in the medial gravels, were derived from the upper lake beds. So far as determined they include an elephant or mastodon, a horse, an ox, and a camel. The fossils are usually scattered through the sediments, more than one or two bones of the same individual being seldom found at a single locality, though the elephant or mastodon bones obtained in the Humboldt Canyon near Rye Patch constitute nearly an entire skeleton. Many of the bones have been removed as curiosities, however, before the collections that were submitted for study were obtained. Recently similar remains have been found in the beach or bar deposits of the former lake near the north end of Pyramid Lake.

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Beyond Golconda the brown, rusty-colored ranges on both sides of the railroad, having characteristic sharp and ragged peaks and ledgy slopes, afford good exposures of the early Mesozoic shales and limestones, very generally associated with lavas.

Eglon and Tule (elevation 4,325 feet) are unimportant stations west of Golconda. Beyond Eglon the railroad bends close around the foothills on the south and is here far enough above the valley to afford an extended view to the north, over Paradise Valley, which is drained by Little Humboldt River. Little use appears to have been made of the lower part of this valley except for grazing and for cutting wild grasses for hay. Beyond Paradise Valley the Southern Pacific turns and for a long distance pursues a general course to the southwest. On the right, ahead, Winnemucca Peak projects like an island from the desert plains. A whitish band along its base is the edge of an extensive area of sand dunes.¹

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¹A large area a few miles north of Winnemucca is covered with sand dunes formed since the disappearance of Lake Lahontan. This belt of drifting sand extends westward from the lower part of Little Humboldt Valley to the desert between Black Butte and the Dona Schee Hills and is about 40 miles long from east to west and 5 or 10 miles wide. The dunes are fully 75 feet thick, and their steeper slopes are on the east side, thus indicating that the whole vast field of sand is slowly traveling eastward. This progress has necessitated a number of changes in the roads in the southern part of Little Humboldt Valley during recent years. In some places in this region the telegraph poles have been buried so deeply that they have had to be spliced in order to keep the wires above the crests of the dunes. The sand is of a light creamy-yellow color and forms beautifully curved ridges and waves that are covered with a fretwork of wind ripples, and many of these ridges are marked in the most curious manner by the footprints of animals, which form strange hieroglyphics that are sometimes difficult to translate.

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The town of Winnemucca, named for a chief of the Piute tribe, is the seat of Humboldt County and serves an extensive ranching and mining country. It was originally a small trading station, established in 1850, on the emigrant route to California and was then known as French Ford. Before the Oregon Short Line was built Winnemucca was the gateway to the whole of southern Idaho. The Southern Pacific and Western Pacific railroads pass through the town about a mile apart, and Humboldt River flows between them. The agricultural and stock-raising districts tributary to Winnemucca include Paradise Valley, to the northeast, and the Quinn River valley, to the north. Of less importance are the narrow bottoms the Humboldt above and below the town, on which the chief crop is wild hay.

The National mining district,² in the Santa Rosa Range, about 70 miles north of Winnemucca, is reached from that town by stage. The National mine is noted for the occurrence of a remarkably rich shoot of ore, which has yielded about $4,000,000.

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²The gold-silver deposits at National were discovered in 1907. The most prominent and widespread rock in the district is basalt, which occurs in a thick series of flows and is probably of Miocene age. The principal ore deposits, however, are associated with older Tertiary lavas, especially with rhyolite and an andesitic rock (latite). The veins were deposited by hot waters soon after the eruption of the rhyolite. They carry quartz, stibnite (sulphide of antimony), free gold alloyed with silver, and other less abundant or less characteristic minerals. Some veins occur also in older rocks.

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After leaving Winemucca the train runs straight down the valley of Humboldt River for several miles, in a course parallel to the river but high on the terraces along its south side. Grass Valley, an extensive depression between the Sonoma Range on the east and the East Range on the west, opens on the Humboldt Valley from the south just west of Winnemucca. From the rear platform the town is seen to stand on a broad, flat, brush-covered alluvial slope, leading down from the mountains on the east to the river channel at the very foot of Winnemucca Mountain. The river bottom lands are but narrow strips, where wild grass is cut for hay.

Beyond Rose Creek (elevation 4,324 feet) the two railroad lines diverge, the Western Pacific taking a route which lies north of the Southern Pacific route and passing out of the valley of Humboldt River.

From Mill City, which was for a long time an important supply and shipping station, roads lead to Bloody Canyon, Star City, Unionville, Chafey (formerly Dun Glen), and other camps that were of note in early days.¹ Most of these camps are south of the railroad.

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¹The discovery of a rich body of silver ore close to the surface in the Sheba mine, on the east side of the West Humboldt Range, due south of Mill city, led to the rapid growth of Star City from 1861 to 1865. The town had two hotels, express and telegraph offices, daily mails, and a population estimated at about 1,000. This was before the building of the railroad, and all supplies were hauled by wagon from Marysville or Sacramento, Cal. In 1871 the town was reported as nearly abandoned. At Unionville there are extensive mine workings dating back to about the same time. Mills were built here at an early date, and from 1860 to 1880 Unionville, although perhaps rivaled or surpassed for a short time by Star City, was on the whole the most important town in the region, as it was the local supply point for many smaller communities in neighboring mining districts. There was considerable activity during the same period near Dun Glen (now known as Chafey).

The Kennedy district, 50 miles south of Winnemucca and about 45 miles by road from Mill City, lies on the east side of the Stillwater Range, and first attracted attention in 1890. Kennedy soon became a flourishing town, mills were built, and considerable work was done in several mines. After the oxidized pay shoots were exhausted the amalgamation mills proved unfit for coping with the complex gold-silver-lead ores, and since 1904 the district has sunk into obscurity. The total output has been estimated at $120,000.

The mines in the West Humboldt Range have yielded far more silver than gold. Most of them were opened and were worked extensively before the completion of the railroad. The great improvement in mining facilities brought about by railroad communication was not sufficient to offset the diminution in tenor of the ore bodies below their enriched portions and the decline in the price of silver.

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The valley of Humboldt River in its course through the old Lake Lahontan sediments takes on a more desolate aspect as the river becomes more deeply intrenched in these barren clays. Apparently no utilization of the narrow river bottoms is attempted here, and the channel, swinging off to the northwest, is soon lost to view from the railroad.

Imlay, a town of recent establishment, is a railroad division point. With its growth Mill City has declined. Due south of Imlay is the north end of the West Humboldt Range, the northern and higher part of which is also known as the Star Peak Range. Here is an excellent example of the characteristically abrupt termination of the basin ranges. The smooth, gradual slope of the alluvial plain sweeps up to the very foot of the mountain front, and foothills proper are lacking.

South of Imlay a fairly abundant supply of good water is found in springs near the base of the mountains and piped down to the railroad. The natural flow from such springs never reaches far beyond the base of the mountain, as the water rapidly sinks in the loose soil or rocky detritus of the piedmont plains. From Imlay to Humboldt the railroad curves around the north end of the Star Peak Range and then, turning almost due south, keeps the west side of this rugged mountain mass in full view. (See Pl. XXXVI, A.)

PLATE XXXVI.—A (top), SNOW ON THE NORTH END OF THE HUMBOLDT MOUNTAINS. View from a point near Imlay, Nev. Photograph furnished by Southern Pacific Co. B (bottom), HOT SPRING NEAR ELKO, NEV. Photograph furnished by Southern Pacific Co.

At Humboldt station is Humboldt House, an old hotel building that was formerly a meal station on the railroad. A good supply of pure water is brought down in pipes from the mountains southwest of Humboldt, making the place an oasis, with trees and green fields. The Ruby quick-silver mine is in Eldorado Canyon, about 8 miles southeast of Humboldt.

The Star Peak Range¹ is rather regular in outline and is about 75 miles long. On the south it is separated by a low pass (Cole Canyon) from the much lower southern division of the West Humboldt Range, sometimes called the Humboldt Lake Mountains. The Star Peak Range culminates in Star Peak, about 10,000 feet above sea level. At its south end is Buffalo Peak, about 8,400 feet in elevation. All along the rugged slopes facing the railroad and also on the opposite side of the range are prospects and mines. One mine, the Star Peak, which is being worked, is almost at the summit of the peak whose name it bears. The Rosebud district, about 28 miles north west of Humboldt, or 35 miles north of Mill City, was the site of a boom that followed the discovery of ore there in 1906. A town was rapidly built, to be as quickly abandoned.

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¹The Star Peak Range is made up of great masses of Triassic rocks belonging to two formations, the Star Peak and the Koipato. The Star Peak formation, the younger of the two, occupies mainly the northern half of the Star Peak Range and has an estimated thickness of 10,000 feet. It is made up of quartzite, limestone, and slates, among which have been found fossil remains of both Middle and Upper Triassic vertebrate and invertebrate animals. These rocks are overlain conformably by limestone and dark slates containing Jurassic fossils. The underlying Koipato rocks, so called from the Indian name of the west Humboldt Range, form a considerable part of the southern half of the Star Peak Range. The Koipato formation was originally described as consisting chiefly of beds of quartzite (silicified sandstone) overlain by inter-stratified beds of limestone, quartzite, and "felsitic porphyroids," and as having an estimated thickness of 6,000 feet. According to later determinations, however, the Koipato consists chiefly of lava flows (rhyolite) with subordinate non-volcanic sediments, including limestones. Much of the rock originally taken to be quartzite is actually rhyolite.

The Triassic slates and limestones of the West Humboldt Range are noted for the abundant and well-preserved fossils found in them. These comprise skeletons of ichthyosaurs "fish lizards," extinct marine animals of large size), spines and teeth of extinct types of sharks, and numbers of the coiled shells known as ammonites.

On the lower slopes of the Star Peak Range are considerable bodies of Tertiary rhyolite and basalt, with which occur related beds of tuffs or other water-laid sediments of about the same age.

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Some mounds about half a mile south of Humboldt, on the right (west) side of the Southern Pacific track, are composed principally of calcareous tufa. Each mound has an opening at the top lined with crystallized gypsum and sulphur. These deposits were undoubtedly made by hot springs that are now extinct. Small pits and an old retort just west of Humboldt mark the site of some old works on these sulphur deposits, but the supply was evidently too small to be of economic importance.

Beyond Humboldt the railroad continues down the east side of the valley over a broad, gently sloping plain of stony detritus and sand, washed down from the mountains. Valery is a sidetrack and loading platform for the Star Peak mine. The mining camp may be seen by looking sharply at the right-hand end of along, dark rocky ridge near the crest of the range. A deep cut along the railroad at milepost 373 exposes a sand and gravel bar, a beach deposit of Lake Lahontan. The old beach lines may readily be traced along the hillsides, particularly late in the afternoon of a clear day. From the rear platform there is now a fine view of the higher part of the West Humboldt Range, which shows a lofty continuous crest with exceedingly steep rocky slopes that contrast sharply with the smoothly graded alluvial fans that spread out from the canyon mouths and coalesce into a gently sloping plain reaching down to the river.

The old hotel building which serves as the station called Rye Patch is a relic of the boom days of the old Rye Patch mine. The name Rye Patch refers to the wild rye grass that formerly grew abundantly about the place. The Rye Patch mine, about 5 miles east of the station, produced much silver ore in the early seventies, but has lain idle for over 20 years. Lately a cyanide plant has been installed, and the old dump is being reworked. The ore occurred in limestone, probably of Triassic age.

PLATE XXXVII.—CHANNEL OF HUMBOLDT RIVER NEAR RYE PATCH, NEV., EXCAVATED IN THE DEPOSITS OF FORMER LAKE LAHONTAN.

After passing Rye Patch the train runs nearly due south, the track lying well up on the broad, gently sloping alluvial plain between Humboldt River on the west and the West Humboldt Range on the east. (See Pl. XXXVII.) Beyond Rye Patch is Zola.