After the discoveries of 1862, gold – dust, nuggets, and quartz ore – poured out of the mountainous Boise Basin region (east of Boise City). Large amounts of silver from Owyhee County, and elsewhere, soon followed. Gold dust immediately became a preferred medium of exchange, as it always did in gold country. The metal has intrinsic value, of course, and can be doled out in widely varying amounts.
|Gold scales. Oregon Historical Society.|
However, the dust also suffers from some serious shortcomings. First, transactions require a set of scales and standard weights to measure the dust. Pioneer Charlie Walgamott noted that Chinese miners in south-central Idaho “invariably” carried their own devices, which were very precise and accurate. (A merchant caught with doctored scales would be in big trouble.)
Such transactions were complicated by the fact that not all gold dust was the same. The nominal value was $16 per ounce. However, dust from one placer area might be worth $12 per ounce while that from another might go $19. The circulation of bogus dust caused further doubt in such dealings.
Private assayers provided a stopgap service by melting dust into gold bars of various sizes. Stamped with the weight, value, and assayer identification, these too could be used as a medium of exchange. However, such “currency” did not travel well … generally only as far as the assayers good name.
Thus, by 1864, miners and businessmen alike were agitating for the establishment of a branch mint within Idaho Territory. Failing that, they wanted at least an official assay office. It simply cost too much to ship the precious metals to the Mint in San Francisco. The 1866 Territorial legislature made a formal request for an assay office, but partisan politics and pressing business at the end of the Civil War delayed action until 1869.
In February of that year, Congress authorized creation of an assay office in Boise City. President Grant then appointed former Idaho Chief Justice John R. McBride [blog, Feb 28] to oversee construction and act as the office’s first superintendent.
|U. S. Assay Office, ca. 1898. Illustrated History image.|
Construction began in 1870 and the Office received its first official deposits in March 1872.
The Assay Office operated as part of the Treasury Department for over sixty years. It processed several billion dollars (in today’s values) worth of gold and silver during that period. The Office closed in 1933 and the U.S. Forest Service began using the building for office space.
Although the interior was extensively remodeled, the exterior of what became a National Landmark was largely unchanged from the original. The National Register states, under Significance, that the Office was “One of the earliest monumental structures in the Northwest … and has always symbolized the importance of Idaho's mines.”
In 1972, the Idaho State Historical Society became the owner of record. Today, the building houses the Idaho Historic Preservation Office and the Archaeological Survey of Idaho.
|Reference: [Hawley], [Illust-State]|
|"Assay Office, Boise," National Register of Historic Places, National Park Service (1961).|
|“The Old Assay Office in Boise,” Reference Series No. 359, Idaho State Historical Society (December 1974).|
|Charles Shirley Walgamott, Six Decades Back, The Caxton Printers, Ltd, Caldwell, Idaho (1936).|