Join Free

Old Maps of Union, Napa for Metal Detecting

Plan your next treasure hunt with 10 historic maps of Union. Find old homesites, ghost towns, trails, and gathering spots that may be lost to time — perfect for identifying promising metal detecting locations.

  • Locate forgotten sites: Uncover places like long-lost settlements, abandoned rail lines, or gathering spots.
  • Plan better hunts: Use map overlays combined with LiDAR or satellite views to narrow in on historically rich areas.
  • Made for detectorists: Thousands of hobbyists use these maps to discover relics, coins, and hidden history.

Use these historic maps to boost your research and find new opportunities beneath the surface of Union.

Union, Napa maps

(10)
  1. 1902 Map of Napa
    1902 Map of Napa
    1902 Napa
    1902 Print · USGS
    Covers Union, including Concord, Vallejo, and other nearby areas
    6 unique versions available
  4. 1942 Map of Sonoma
    1942 Map of Sonoma
    1942 Sonoma
    1942 Print · USGS
    Covers Union, including Napa, Sonoma, and other nearby areas
  7. 1947 Map of Santa Rosa
    1947 Map of Santa Rosa
    1947 Santa Rosa
    1947 Print · USGS
    Covers Union, including Santa Rosa, Concord, and other nearby areas
  10. 1949 Map of Santa Rosa
    1949 Map of Santa Rosa
    1949 Santa Rosa
    1949 Print · USGS
    Covers Union, including Santa Rosa, Concord, and other nearby areas
    2 unique versions available
  13. 1951 Map of Napa, 1952 Print
    1951 Map of Napa, 1952 Print
    1951 Napa
    1952 Print · USGS
    Covers Union, including Napa, Imola, and other nearby areas
    6 unique versions available
  16. 1951 Map of Sonoma, 1958 Print
    1951 Map of Sonoma, 1958 Print
    1951 Sonoma
    1958 Print · USGS
    Covers Union, including Napa, Sonoma, and other nearby areas
    3 unique versions available
  19. 1958 Map of Santa Rosa, 1968 Print
    1958 Map of Santa Rosa, 1968 Print
    1958 Santa Rosa
    1968 Print · USGS
    Covers Union, including Santa Rosa, Concord, and other nearby areas
    3 unique versions available
  22. 1962 Map of Santa Rosa
    1962 Map of Santa Rosa
    1962 Santa Rosa
    1962 Print · USGS
    Covers Union, including Santa Rosa, Concord, and other nearby areas
  25. 1964 Map of Santa Rosa
    1964 Map of Santa Rosa
    1964 Santa Rosa
    1964 Print · USGS
    Covers Union, including Santa Rosa, Concord, and other nearby areas
  28. 1983 Map of Napa
    1983 Map of Napa
    1983 Napa
    1983 Print · USGS
    Covers Union, including Santa Rosa, Concord, and other nearby areas
End of results
Showing maps 1-10 of 10

Top cities near Union

See more

Frequently asked questions

  • What are the different types of historical maps available for Union?
  • What is the oldest map of Union?
  • Where can I purchase historical maps of Union for my home or office?
  • Where can I download high-res historical maps of Union?
  • Are there historical topographic maps available for Union?
  • Is there historical aerial imagery available for Union?
  • Where are historical maps of Union sourced from?