Downtown in Boise in Ada County, Idaho — The American West (Mountains)

A Capital Investment

Photographed by Douglass Halvorsen, July 4, 2026

1. A capital Investment Marker

Inscription. Idaho Territory was remote and hard to get to. Early on, there were no trains, only rough roads and trails over difficult terrain. The closest US Treasury Department offices were in Denver or San Francisco. This made it hard and expensive for miners to cash in their gold and silver.

For several years, miners and Idaho leaders asked Congress for a federal Treasury facility in the territory. Local businessman Alexander Rossi offered to donate an entire city block for that use. In 1869, Congress approved a new assay office and the money to build it in Boise.

Inset
To assay means to test metal or ore for quality and purity. Miners and the public brought silver and gold nuggets or dust to this building to be assayed. The federal government then paid cash for these precious metals and added them to the nation’s reserves.

Timeline
From Time Immemorial - Indigenous People
1869 - 1932 - US Treasury Department
1932 - 1972 - US Forest Service
1972 - present - Idaho State Historical Society

Erected by Idaho State Historical Society.

Topics. This historical marker is listed in this topic list: Industry & Commerce. A significant historical year for this entry is 1869.

Location. 43° 36.789′ N,

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116° 11.81′ W. Marker is in Boise, Idaho, in Ada County. It is in Downtown. It is on N 3rd Street, on the left when traveling south. Touch for map. Marker is at or near this postal address: 210 W Main Street, Boise ID 83702, United States of America. Touch for directions.

Regionally, this marker is on Idaho’s Snake River Plain.

It is also in the American Mountain West.

Globally, it is in North America,

the Western Hemisphere,

the Western World,

and the Anglosphere.

Other nearby markers. At least 8 other markers are within walking distance of this marker: “The Finest in the Territory” (here, next to this marker); “Silver & Gold in the Sunlight Blaze” (within shouting distance of this marker); Assay Office (within shouting distance of this marker); U.S. Assay Office (within shouting distance of this marker); Working from Home (within shouting distance of this marker); “Lovely Lawns Carefully Kept” (within shouting distance of this marker); Treasure to Timber: A Site in Transition (about 300 feet away, measured in a direct line); A Lasting Legacy (about 300 feet away). Touch for a list and map of all

Photographed by Douglass Halvorsen, July 4, 2026

2. A Capital Investment Marker

markers in Boise.

Credits. This page was last revised on July 10, 2026. It was originally submitted on July 10, 2026, by Douglass Halvorsen of Klamath Falls, Oregon. This page has been viewed 7 times since then. Photos: 1, 2. submitted on July 10, 2026, by Douglass Halvorsen of Klamath Falls, Oregon. • Andrew Ruppenstein was the editor who published this page.