Friday, October 24, 2008

Arbuckle Mountain, Oregon

Last weekend the North America Research Group (NARG) sponsored a fossil dig at Arbuckle Mountain, about 20 miles southeast of Heppner, Oregon. The big attraction here is a giant palm frond, Sabalites eocenica, from the Eocene Clarno Formation. In addition to palm fronds that can reach four feet in size, the area is noted for avocado, magnolia, willow, and other leaves. There is a weak lignite zone through the area, with some short-lived coal beds worked at nearby Coal Mine Hill.

Some of the NARG team camped at Arbuckle Corral on Friday night; others stayed in town or made other arrangements. Digging began in earnest before noon on Saturday. Soon the team had zeroed in on a productive strata. Tim Fisher, who lists about ten separate GPS coordinates for this area on his invaluable OreRockOn DVD and website ( soon got into a nice zone and pulled out an unidentified flower, along with palms about a foot in length. The team also recovered nice specimens of cypress and metasequoia.

Tim's zone extended across the top of the road cut, and at least five different excavations produced good material. The team continued digging until dinner, retired to an excellent meal around a roaring campfire, and settled down to a cool evening in the pine forests of eastern Oregon.

The next morning, the team went back at it. We cleared some more material, gathered up the best stuff, emptied out the ditch along the road to keep the Forest Service happy, and generally cleaned up. A nice lady came down the road in an ATV with a big harvest of Shaggy Mane mushrooms, but she reported that there was a new gate at the top of the road.

For an October fossil search and rescue, the weather was ideal. Maybe that was why the camaraderie was so great, but I don't think it's the only reason. I'm always struck by how easy it is to get along with other fossil hunters, rockhounds, and gold prospectors. We shared a ton of information over the campfire, pressing each other for insight into new areas. I like that part the best; there are so many spots to hit out here.

I know I should put the GPS coordinates in this article, but I'm going to resist the temptation. Join NARG at and you can visit the area with us next year!


The Ore Bin, June 1961

The Oreg Bin, May 1969

Friday, October 10, 2008

Idaho's Yankee Fork dredge

Mining the Internet: Yankee Fork Dredge

By Garret Romaine
(this article will appear in the next issue of Gold Prospectors magazine; sorry about the length)

Driving west last summer from Challis, Idaho, toward the interesting town of Stanley, I took ID 75 as it followed the Salmon River for mile after scenic mile. The Sawtooths loomed on the horizon, while alpine forests dipped down to transition into sagebrush hills. Some tantalizing gravel bars were just emerging from the low water of late August, offering opportunities to search for agate, jasper, and petrified wood, or wash some gravel for black sands and fine gold. Mentally plotting the mileage from here to Portland, Oregon, I reached the tiny crossing at Sunbeam and saw a sign for the Yankee Fork dredge. Somewhere in the dim recesses of my gold-fevered brain, a light went off. I seemed to remember this area was once a major producer. Besides, there was that word ‘dredge.’ On the spot, I detoured north onto Yankee Fork Road. And I’m really glad I did.

In this article, I’ll describe the Yankee Fork district in detail. I’ll provide you with the history of the Yankee Fork gold rush, culled from some dependable research materials. I found two excellent descriptions of the actual “eureka!” moments when prospectors located fabulous quartz veins. In addition, I’ll share some web links that briefly describe the recreational activities available to current visitors during those brief summer months when the area is most hospitable. With ghost towns, museums, abandoned mines, and that magnificent dredge as a base, the Yankee Fork of Idaho’s Salmon River has a lot to offer


First off, let’s answer the basic question: how rich was it? According to the U.S. Geological Survey:

“Anderson (1949, p. 14) credited the district with a total production of gold and silver valued at $13 million to about 1948. Of this, $12 million was mined before 1910. Umpleby (1913a, p. 78) estimated that about 40 percent of this was in gold (about 252,000 ounces). From 1948 through 1959 the district produced 14,253 ounces; most of it was from dredging operations. Total gold production through 1959 was about 266,600 ounces.” (USGS Bulletin 610, p. 128)

That’s a good haul, by any yardstick. Interestingly, the district started slowly, as access was difficult, there were no railroads anywhere near the area, and the Boise Basin discoveries were much easier to reach. The original discovery in this district was at Loon Creek, about 30 miles north of Sunbeam, as Sparling describes in Ghost Towns of Southern Idaho:

“When Nathan Smith discovered placer gold on Loon Creek in 1869, he set off another rush into the back country…Near the mouth of Canyon Creek, the tent and log town of Oro Grande began to take shape... In 1879 five Chinese miners were killed by Sheepeater Indians. There is some doubt as to whether Indians committed this crime or white men intent on robbing the Chinese of their gold, but the incident helped touch off the Sheepeater Indian War... The town site was burned over years ago and nothing remains today. The next settler at the mouth of Canyon Creek was Billy Casto, and on most maps, the site of Oro Grande is shown as Casto.” (Sparling, pgs. 95-100)

Loon Creek proved to be a flash in the pan save for the Lost Packer mine. In his classic book, Gold Camps and Silver Cities, Merle Wells picks up the story:

“Yankee Fork got off to a surprisingly slow start. Joel Richardson and a party of Yankee prospectors examined Yankee Fork while traveling through that part of the country in 1866 or 1867. Aside from bestowing a name on the stream, they left little imprint before retiring to Montana. By 1868, a few men were washing out gold at nearby Robinson Bar [on the Salmon River]. After the rush to Loon Creek in 1869, mining was under way on both sides of Yankee Fork.

“Prospectors radiated out in all directions from Loon Creek. D.B. Varney and Sylvester Jordan brought a group of miners over to Yankee Fork in 1870, where most of their claims proved a disappointment. Only one of the new Jordan Creek claims yielded enough (in this case, $10 per man a day) to justify working. The next spring the decline of Loon Creek inspired two more gold hunters to cross over to Yankee Fork. They had a hard time of it. According to Clitus Barbour, ‘Arnold and Estis (Estes) the discoverers of Yankee Fork camp, toiled in the snow and storm twenty-five days transporting their supplies in there on sleds from Loon Creek, a distance of only twenty-five miles, over a divide thousands of feet high.’ On the strength of opening discovery claims good for $8 a day, about twenty miners organized a district and went to work. By the end of July, five companies were preparing their claims for mining. Fifty or sixty men, mostly from Loon Creek, were on hand. Some of them ‘were busy opening their claims, while others were running up and down the river, uncertain what to do, and waiting for the turn of events.’ Not until the new claims turned out profitable did the doubters go to work. Even then Yankee Fork attracted little outside interest. Only fifteen men spent the winter, and no grounds for a stampede materialized in 1872. Lode discoveries, in fact, did not come on any important scale for three more years.” (Wells, pg. 118)

So early placer mining was barely productive. Because these were experienced prospectors, they knew the source for the gold must be nearby, and the search would heat up again each spring once the snow melted. Here’s the description of the big discovery, again from Wells:

“Searching on a Sunday afternoon in June 1875 for the lodes from which Jordan Creek’s extensive, but otherwise unimpressive, placers originated, W.A. Norton came across the vein that every prospector dreams of finding one day. Very few ever had his kind of luck. In a high-grade vein he found a seam of exceptionally rich ore only two or three inches thick. With the help of a partner or two, he was able to pound out $11,500 worth of gold in a hand mortar in thirty days. That was enough to pay some oppressive debts and to start developing the mine. No rush to Yankee Fork attended Norton’s discovery of the fabulous Charles Dickens, as it was called. His find went by almost unnoticed. Then, when winter struck early, Yankee Fork was depopulated almost entirely. Packers had no opportunity to supply the high mountain camps. Yankee Fork was reduced to a population of only three, while neighboring Loon Creek declined to four.” (Wells, p. 118)

Winters in this area can be deadly, as elevations start at about 6000 feet where the Yankee Fork meets the main stem of the Salmon. Snow often piles up over ten feet deep, temperatures drop below zero and stay there, and opportunities to hunt for game are scarce. That must have been one dismal camp. But surely one of the reasons the men stayed put was the opportunity to find another ledge like the Charles Dickens.

Wells picks up the story the next year:

“When prospectors resumed in 1876, other extremely rich lodes followed the Charles Dickens. Most notable of all was the General Custer which James Baxter, E.M. Dodge, and Morgan McKeim discovered on August 17. In a manner somewhat different from the Charles Dickens, with its wealth of ore suitable for hand mortaring, the Custer also rated as a prospector’s dream. In this discovery, most of the vein happened to lie exposed on the surface. (The way miners describe it, most of the hanging wall simply had slid off the vein.) Thus the miners could avoid much of the expensive development work (that is, driving tunnels and raises or shafts deep into the mountain along a mineralized vein in order to verify the presence of enough ore to justify bringing in a mill) ordinarily required before a prospector could sell out his discovery. Erosion had done most of the development work. Moreover, the relatively low cost of getting out high-grade ore from the Custer enhanced its value greatly. One man could pull down twelve tons of ore a day. E.W. Jones reported in 1877: “The owners merely break the ore loose…tumble it down in large masses to the dump, break it up, sort it and sack it.” At that point, the ore was ready for packing to a mill in Salt Lake City, where $60,000 was realized from the small open cut. Somehow even this marvelous discovery did not generate an old-fashioned gold rush to Yankee Fork.” (Wells, pgs. 119-120)

Now stampeders flocked into the area. Soon the nearby towns of Bonanza City and Custer sprang to life, as described by Sparling:

“The rich placers along the Yankee Fork and up Jordan Creek encouraged the miners to build Bonanza City in 1876. By 1880 the town had fifteen hundred people, a post office, stores, hotel, many houses, and a newspaper, The Yankee Herald. Prior to 1880, Bonanza and Custer were supplied by freighters using pack strings of horses or mules, and the demands of these towns was largely responsible for the growth of Challis as a supply center. Since nearby Custer didn’t have a cemetery, the one back in the hills behind Bonanza served both communities. Some log building remain along the road in Bonanza, but many have tumbled down and been destroyed…

“Situated about two miles upstream from Bonanza, Custer grew with the development of the rich quartz mines. The Charles Dickens was the first big mine, and others nearby were the General Custer, the Lucky Boy, the Black Mine, and the Montana Mine. With the defeat of General Custer in 1876 still fresh in their minds, the miners named the town in his honor. A toll road over Mill Creek to Challis was opened in 1880 and allowed freighters to bring in the heavy machinery that a mill required. The Custer Mill started operating in 1881 and closed down in 1903, and at one time it had thirty stamps going. A tramway was built up the mountainside behind the mill to carry down the ore. Unfortunately the mill has been burned down and only the foundations remain.” (Sparling, p. 97)

As happened in many remote districts, land ownership issues cropped up early in the development of the better properties. However, the legal problems were nothing that a little outside capital from California couldn’t solve, as Wells describes.

“By the spring of 1879, Joseph Pfeiffer of Rocky Bar had brought in San Francisco engineers and capital, and had arranged purchases enough to enable work and production at the Custer to resume. ‘People generally thought him crazy’ to be investing so heavily in an undeveloped prospect located hundred of miles from a railroad and on a practically unimproved pack trail ‘in a wild, sparsely-settled country, surrounded by hordes of hostile Indians.’ Yet Pfeiffer had recovered his initial $60,000 investment by shipping ore to Salt Lake City, and his California associates, who included George Hearst and the president of Wells Fargo, supplied the balance (over twice that amount) to straighten out title. The next step was to stop hauling ore by pack mule to distant mills in Atlanta or Salt Lake; freight costs to Blackfoot, where rail service was available by 1879, ran $100 a ton. Then George Hearst induced Alexander Toponce to build a toll road to Challis, over which stage service to Bonanza commenced on October 3, 1879. Toponce’s road made it possible for Pfeiffer’s San Francisco capitalists to bring in a thirty-stamp mill for the Custer. In spite of all the excitement, production at Yankee Fork mines amounted to only $420,000 in 1879. Then, ‘after many unavoidable and tedious delays,’ the Custer mill was completed at the very end of 1880. Production in 1881 rose immediately to over $1 million. The Yankee Fork mines at last were showing their great potential.” (Wells, p. 123)

Government geologists soberly relate the rest of the story:

“However, these high-grade deposits proved to be shallow, and the district began to decline in the 1890’s, and its mill closed in 1905. There were sporadic attempts to revive some properties, but no significant activity occurred until the reopening of the Lucky Boy mine in 1939. Placer mining along the Yankee Fork was also renewed about that time. World War II curtailed activities, but a few properties were reopened in 1946 and 1947. Production in the late 1940’s was almost entirely by a dredge that operated along the Yankee Fork, although small-scale production from lode deposits continued through 1957 (T. H. Kiilsgaard, written commun., 1962). The most productive placers in the district were along the Yankee Fork of the Salmon River, from the mouth of Jordan Creek almost to the mouth of the Yankee Fork.” (USGS, p. 128)

No detailed description of a mining district is complete without at least summarizing the geology reports. If you get a chance to explore some of the abandoned mines and their tailings piles, you need to know what to look for. In addition, the gravels that have been turned upside down along the Yankee Fork are worth exploring with a heavy hammer, in hopes of busting up a quartz chunk and revealing some interesting minerals. So even though this next paragraph can be heavy slogging, I feel duty-bound to include it in this writeup. All the usual players for Idaho are present: old rocks from the Paleozoic and Mesozoic Ages, and a healthy dose of that great lump of granite, the Idaho Batholith:

“Bedrock in the Yankee Fork district, according to Anderson (1949, p.8-11) consists of contorted Paleozoic and Mesozoic sedimentary and volcanic rocks that are intruded by quartz monzonite and granodiorite of Mesozoic age. The Paleozoic rocks are the Wood River Formation of Pennsylvanian age and the Casto Volcanics of Permian (?) age. These are cut in the northwest part of the district by quartz monzonite of the Idaho batholith. The Paleozoic rocks were subjected to two periods of deformation - one at the close of the Jurassic and one at the close of the Cretaceous. During Oligocene time the Challis volcanic flows covered most of the older rocks, and these were intruded in Miocene time by relatively small masses of dacite and rhyolite porphyry (Anderson, 1949, p. 8-10). The Challis Volcanics were gently warped and fractured, and these fractures were filled by epithermal silver-gold deposits. Most of the lodes are simple fissure fillings, but where the rock was complexly fractured, the ore minerals are disseminated and the deposits resemble stockworks (Anderson, 1949, p. 15). Typical vein filling is quartz, which may be fine grained, coarse comb, or drusy. Veins characteristically contain pyrite, chalcopyrite, sphalerite, tetrahedrite, arsenopyrite, enargite, galena, stephenite, miargyrite, pyargyrite, argentite, aguilarite, gold, and electrum; some calcite may be present. In the weathered zones, native silver, argentite, cerargyrite, azurite, malachite, chalcocite, and covellite are present in various amounts.” (Anderson, 1949, p. 16-17).

Dredge Links
By far the most interesting aspect of a drive up the Yankee Fork is the big dredge near Custer. There are several links on the Internet that can direct you to historical facts about the massive dredge, plus information about the fascinating museum at Custer that attracts thousands of visitors each year. Entry fees are quite reasonable for both the dredge tour and the museum visit, and they’re both family-friendly. I’ve weeded down and snipped a bit of representative text for each link below.

US Forest Service
“In 1979, the Yankee Fork Gold Dredge Association was chartered by former employees and their families. This dedicated, hardworking group of volunteers has restored the dredge and it is open for guided tours. This fascinating tour is open from Memorial Day through Labor Day weekend from 10:00 A.M. to 4:30 P.M. They will even show you how to pan for gold!”

Sun Valley Guide
“Ghostly remnants of another Idaho mining boom-and-bust linger along the nine miles of dirt road just north of the Sunbeam Dam and Yankee Fork turnoff on state Highway 75. Wooden shards, remnants of homes that once occupied the exuberantly named settlement of Bonanza, lay between the trees. Cabins, better-preserved icons of what passed for civilization in the 19th century wilderness, stand farther along the road in Custer. Between these relics of the Old West looms a brooding artifact, a younger cousin to those mining yesteryears that seems, at first glance, to be just a mirage in the backwoods of lush forests and richly stocked fishing streams.

“The word behemoth is insufficient to describe the giant Yankee Fork gold dredge. It is a grayish monster languishing in its final resting place, a mechanical dinosaur idling in a perpetual pond, now serving only as a fascinating curiosity for tourists. Turn the clock back 60 years and the dredge resembled a well-lighted, four-story hotel; and it had a purpose. It spent its days swinging a giant arm to gouge and sift earth by the tons per minute in search of gold.”

Oregon State University pictures collection|r
I know that’s a lot to type; you can Google for ‘Yankee Fork Dredge pictures’ and get there just as fast. Great old black and white photos here.

Suite 101 motorcycle adventures
“Designed by the Bucyrus-Erie Company for the Snake River Mining Company to suit the specific geology along the Yankee Fork, work crews constructed this 988-ton, 112-foot long, 54-foot wide and 64-foot high dredge next to the river where it floated in a pond of its own making.

“From 1940 to 1953, the dredge traveled relentlessly upriver for a total of five and one-half miles. It operated 24-hours a day except from late fall until early spring when ice and cold caused its shutdown. During its 13 productive years, the dredge turned six million cubic yards of stream gravel into more than 1 million dollars worth of gold and silver. In 1966, its last owner donated the dredge to the Forest Service.”

Yankee Fork Dredge State Park
“At Sunbeam, interpretive signs describe the beautiful Salmon River and the remnants of the Sunbeam Dam, the only dam ever constructed on the Salmon. The dam was built in 1910 to generate electricity for nearby mines. The operation went bankrupt in 1911 and the dam was breached in 1934.”

Off Road Explorers
“Despite being abandoned for a half century and having the occasional band of hippies residing in it during the 1970’s, the dredge is amazingly intact. It has been somewhat restored by a group of volunteers who work with the forest service and give tours of the dredge for a small fee.”

Historic Photo Archive
“In the early 1930's several placer miners joined together to form a company to see if they could get someone interested in dredging their claims on the Yankee Fork. Twenty-nine claims were involved. During 1938 and 1939, the Silas Mason Co. of Shreveport, Louisiana became interested. When tests indicated approximately $16,000,000 worth of gold was recoverable, they formed a subsidiary, the Snake River Mining Co., to manage the dredging. The Bueyrus-Erie Company was awarded a contract to build the dredge in 1939 and completed it in the fall of 1940. The Olson Manufacturing Company manufactured most of the steel work in Boise, Idaho. The parts were shipped by train to Mackay, then hauled by trucks to Yankee Fork and assembled in 1940.”

Vital Guide Books
Short QuickTime movie about the dredge.

Go Northwest
Information about the town of Stanley:
“In summer, the small town swells with visitors who use Stanley as a base for exploring the Salmon River, the Sawtooth National Recreation Area, and other public lands. Popular in summer are rafting, float trips, hiking, fishing and hunting, and in winter, snowmobiling and cross-country skiing… The town takes its name from the surrounding basin, itself named for Captain John Stanley, a Civil War veteran. He was leading a party of prospectors who passed through the basin on their way to Idaho City. The party found a small amount of placer gold, and Stanley didn't return but one of the party, A.P. Challis, did and mined around Stanley for many summers.”

There are developed campgrounds between Sunbeam and Bonanza City, plus more campgrounds near Casto. I see more camping areas on the road from Custer to Challis, and there must be eight developed sites along the Salmon on either side of Sunbeam. Contact the Chalis-Yankee Fork Ranger District office at Challis: (208) 879-4100 or on the web at Many campgrounds in this area can be reserved over the web.

There are some current claims being worked in and around the massive dredge tailings below Bonanza City, where apparently some unworked ground escaped the big dredge. I witnessed one person with a metal detector walking through the tailings, but there were probably a dozen fishermen out that day. Many small streams that empty into the drainage are worth exploring, particularly above Custer and further up the rough road to Loon Creek/Casto. Topo maps for this area show many mines and prospects worth checking out if you have time. There is a huge open pit operation west of Custer, along Jordan Creek, so watch for heavy truck traffic during normal business hours.


Anderson, A. L., Silver-Gold Deposits of the Yankee Fork District, Custer County, Idaho. Idaho Burau of Mines and geology Pamphlet 83. 1949. 37 pgs.

Koschmann, A.H., and Bergendahl, M.H., Principal Gold-Producing Districts of the United States, U.S. Geological Survey Professional Paper 610. 1968. 283 pgs.

Sparling, Wayne C., Southern Idaho Ghost Towns, Caxton Printers Ltd., Caldwell Idaho. 1996. 135 pgs.

Wells, Merle W., Gold Camps and Silver Cities: Nineteenth-Century Mining in Central and Southern Idaho, University of Idaho Press, Moscow, Idaho. 2002. 233 pgs.

Umpleby, J. B., Some Ore Deposits in Northwestern Custer County, Idaho, U.S. Geological Survey Bulletin 539, 1913. 104 pgs.