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.
Tap the map once at the new site location · cancel
Fill = type:
mudflat
river
dump
foreshore
lake
wreck
dive
ghost town
prohibited
Ring = evidence: ● T1 source-confirmed (strongest) ● T2 documented ● T3 inference
Tiers rate the paper trail (maps, archives, reports), not a site visit. Mudlark researches remotely; ✓ yours = your own logged finds.
Pin: verified spot · right waterway (close) · town only (≈) = you localize with the historic maps
Open site: amber ring marks the spot you have open (hover for its name, click to reopen); an approximate spot shows an amber zone instead
Confidence view (Filters > Map): green=confirmed finds, blue=documented, amber=inference; opacity = pin confidence
Rocks & gems: crystal agate gold fossil mineral opal amber
Before you dig: Mudlark is a research tool, not permission. Confirm access and ownership and obey all local laws; a listing is never a legal right. You are responsible for your own actions. Terms · Privacy
Ring = evidence: ● T1 source-confirmed (strongest) ● T2 documented ● T3 inference
Tiers rate the paper trail (maps, archives, reports), not a site visit. Mudlark researches remotely; ✓ yours = your own logged finds.
Pin: verified spot · right waterway (close) · town only (≈) = you localize with the historic maps
Open site: amber ring marks the spot you have open (hover for its name, click to reopen); an approximate spot shows an amber zone instead
Confidence view (Filters > Map): green=confirmed finds, blue=documented, amber=inference; opacity = pin confidence
Rocks & gems: crystal agate gold fossil mineral opal amber
Before you dig: Mudlark is a research tool, not permission. Confirm access and ownership and obey all local laws; a listing is never a legal right. You are responsible for your own actions. Terms · Privacy