U. S. Assay Office, 210 Main Street, Boise, Ada County, ID

Significance: One of the earliest monumental structures in the Northwest, the Assay Office opened in March 1872. It was designed in Washington, D.C. by A.B. Mullett's office, the office of the supervising architect of the Treasury Department. The building operated as an assay office from 1872-1933, and has always symbolized the importance of Idaho's mines. The State plans to turn this venerable structure into a mining museum.
Unprocessed Field note material exists for this structure: FN-19
Survey number: HABS ID-10
National Register of Historic Places NRIS Number: 66000305