Questions about Bourn Cottage (Empire Cottage, Empire Mine)
What design work is credited to Willis Polk at Bourn Cottage (Empire Cottage, Empire Mine)?
Willis Polk designed Bourn Cottage (Empire Cottage, Empire Mine).
More documented details
Bourn Cottage (Empire Cottage, Empire Mine) is in Grass Valley.
Sources: SRC-2719 · SRC-2720 · SRC-3788
The recorded construction date for Bourn Cottage (Empire Cottage, Empire Mine) is 1897.
Sources: SRC-2719 · SRC-2720 · SRC-6894
The recorded style of Bourn Cottage (Empire Cottage, Empire Mine) is English-style manor (English country estate / English Revival).
Bourn Cottage (Empire Cottage, Empire Mine) is a Tudor Revival cottage in Grass Valley, California. Built in 1897, it was designed by Willis Polk, and is listed on the U.S. National Register of Historic Places.
Location: Grass Valley, California, United States
Verified facts
- Located in Grass Valley
confidence 85/100 · 3 recorded source groups · SRC-2719, SRC-2720, SRC-3788 - Designed by Willis Polk
confidence 80/100 · 5 recorded source groups · SRC-2719, SRC-2721, SRC-6892, SRC-6893, SRC-9829 - Built in 1897
confidence 70/100 · 3 recorded source groups · SRC-2719, SRC-2720, SRC-6894 - Architectural style: Tudor Revival
confidence 75/100 · 4 recorded source groups · SRC-2720, SRC-2719, SRC-6895, SRC-6894 - Historic designation: National Register of Historic Places; California Historical Landmark
confidence 85/100 · 3 recorded source groups · SRC-2719, SRC-2722, SRC-2921
Evidence & sources
- SRC-2719 — Empire Mine State Historic Park — Wikipedia (Tier 2, encyclopedia; retrieved June 2026)
- SRC-2720 — Grass Valley — Visit California (Tier 2, official_tourism; retrieved June 2026)
- SRC-2721 — A Grass Valley landmark home is gone but not forgotten — The Union (Tier 2, news; retrieved June 2026)
- SRC-2722 — Empire Mine — California Office of Historic Preservation (Landmark No. 298) (Tier 1, official_archive; retrieved June 2026)
- SRC-2921 — National Park Service — NPGallery, National Register of Historic Places Asset Detail: Empire Mine (NRIS ID 77000318) (Tier 1, official_archive; retrieved June 2026)
- SRC-3788 — ca.gov (Tier 1, official_primary; retrieved June 2026)
- SRC-6892 — Inspired Imperfection – Empire Mine State Historic Park (Tier 3, travel / history feature; retrieved June 2026)
- SRC-6893 — Clio – Bourn Mansion (Tier 3, public history platform; retrieved June 2026)
- SRC-6894 — Digital Public Library of America (DPLA) — The Bourn Cottage, Empire Mine State Historic Park (Tier 2, library/archive-metadata; retrieved June 2026)
- SRC-6895 — Highway 49 Gold Rush Country: Grass Valley – Empire Mine State Historic Park – Weekend Adventures Update (Tier 3, media; retrieved June 2026)
- SRC-9829 — History of Empire Mine — Sierra Gold Parks Foundation (Tier 2, official_site; retrieved June 2026)
How we verify
The entries above show the sources and confidence scores recorded in our fact ledger.
Source tiers are internal classifications, not guarantees of accuracy or independence.
Several sources may repeat the same underlying account; a source count alone does not establish independent corroboration. We show the
street address only for non-residential public landmarks (museums, commercial and civic buildings,
publicly documented filming-location sites); the exact addresses of private residences and any
personal information are structurally barred from publication. Last reviewed June 2026.