Assay Office
Added to the National Register in 1966, and a National Historic Landmark.
The record
| Property type | Building |
| Address | 210 Main St., Boise, ID |
| County | Ada County |
| Listed | Oct 15, 1966 |
| Listed for | Commerce, Exploration and settlement, Politics and government, Architecture |
| Level of significance | National |
| Reference number | 66000305 |
| Architect | Alfred B. Mullett |
| Designations | National Historic Landmark |
The nomination form, the document that argues why this place matters, is in the National Archives: Read the nomination ↗
Visiting
| Address | 210 Main St., Boise, ID |
| Coordinates | 43.6114° N, 116.1960° W · Directions ↗ |
| Also in Boise | 145 listed places in Boise → · walking tours → |
Explore
Map
Nearby in Ada County
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Local history books for Boise
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Idaho travel guides
Titles come from Open Library's catalog, matched by subject heading or by title.
Reference
Questions people ask
When was Assay Office listed on the National Register?
Oct 15, 1966. It is also a National Historic Landmark, the higher of the two designations.
Source: National Park Service
Who designed Assay Office?
Alfred B. Mullett.
Source: Wikidata
Where is Assay Office?
210 Main St., Boise, Ada County, Idaho.
Source: National Park Service
Where is the nomination form for Assay Office?
The National Archives holds the nomination form, the document that made the case for listing.
Source: National Archives
Is there a wildfire near Assay Office right now?
1 active incident within 50 miles as of 2026-10-17, nearest Rx Lowman Wui, 50 miles away.
Source: Map
Sources
Name, location, type and dates come from the National Register office's spreadsheet of listed properties, because the Park Service's spatial data does not carry this listing. The map point comes from Wikidata. Construction date, architect, style, photograph and encyclopedia link come from Wikidata and Wikimedia Commons, matched on reference number 66000305. Nothing here is transcribed by hand. The nomination form and photographs ↗ at NPGallery are the original nomination as filed with the National Park Service, and the form is often the best description of the place.