Pre-1900 glass sites · tide-timed · evidence-tiered
Data, export & creditsMap layers: LOC Sanborn · topoView · NOAA T-sheets · Rumsey · NLS (UK)
Coords approximate. Verify land status before digging. Tides: NOAA CO-OPS live.
Click the map at the new site's location · cancel
Fill = type:
mudflat
river
dump
foreshore
lake
prohibited
Ring = evidence: ● T1 my finds ● T2 documented ● T3 inference
Pin: verified spot · right waterway (close) · town only (≈) = you localize with the historic maps
Confidence view (Filters > Map): green=your finds, blue=documented, amber=inference; opacity = pin confidence
Ring = evidence: ● T1 my finds ● T2 documented ● T3 inference
Pin: verified spot · right waterway (close) · town only (≈) = you localize with the historic maps
Confidence view (Filters > Map): green=your finds, blue=documented, amber=inference; opacity = pin confidence