James F Bailey Assay Office Museum
- Also Known As: Wallstreet Assay Office
- Also Known As: Bailey Residence
- Address: 6352 Four Mile Canyon Dr
- Vicinity: Rt 118, Salina Star Rt
The Wallstreet Assay Office Building is a simple, but substantial, commercial building located in the heart of Wallstreet, a tiny mountain community of Boulder County, Colorado. The building is one of the only intact structures related to precious metal mining that remains in Wallstreet and the county. The site of the Assay Office is adjacent to Four Mile Creek and the roadway that traverses the narrow canyon floor. Although settled since the late 1800 and only a short distance from the metropolitan area of Boulder, Wallstreet is distinctly rural in character. Heavily wooded slopes surround the Assay Office and large stands of scrub oak are interspersed among the buildings nearby. Just to the west of the Assay Office looms the fortress-like remnants of the Wallstreet Gold Extraction Mill. - NPS