Reading Lodester's Map Layers
Lodester stacks several independent datasets so you can ask one question from many angles: where might gold be, and can I legally go there? Each layer answers part of it. The skill is reading them together.
The geoscience layers
- Geology — bedrock map units (from the USGS State Geologic Map Compilation), colored by lithology or age. Gold favors certain hosts and settings, so geology is your first filter for favorable ground.
- Structure — faults, contacts, and shear zones. Lode (hard-rock) gold is strongly controlled by structure; veins follow these breaks in the rock.
- Hydrology — rivers and water bodies (USGS NHD for the US, plus global HydroRIVERS). Placer gold is moved and concentrated by water, so streams and their bedrock are where placer hunters work.
- Magnetic anomaly — the EMAG2 magnetic field (NOAA). Magnetic highs and lows can flag intrusions, structures, and rock types that aren't obvious at the surface.
- Shaded relief / terrain — the lay of the land: drainages, ridges, and access.
The mineral-occurrence layers
- Mines (USGS MRDS) — recorded mineral sites, with gold occurrences emphasized. These are known points: places where gold has already been found or worked. Caveat: MRDS has been frozen since 2011 and varies in precision, so it shows history, not the present.
- Gold-occurrence density — a smoothed (kernel-density) surface built from the MRDS gold points: where gold occurrences cluster. It answers "is this a gold neighborhood?" rather than "is there gold on this spot?"
- Prospectivity — a derived index that combines favorable geology × gold-occurrence density. It is a heuristic to rank ground, not a prediction or a guarantee. High prospectivity means "worth a closer look," nothing more.
The land and reference layers
- Public lands — surface management agency (BLM and others), the starting point for whether ground is open. Pair it with the live land & claims panel for active mining claims.
- Lost Treasures — the catalogue of lost-treasure cases; remember every point is a search-area center, never the treasure.
Reading them together
A practical stack for placer: gold-density to find the neighborhood, hydrology to find the streams, geology + structure to understand why gold is there, and terrain to plan access. For lode: favorable geology + structure, cross-checked against nearby MRDS occurrences. Then — before anything else on the ground — public lands + claims to confirm you can legally be there.
In Lodester
Toggle layers to test an idea, not to confirm a hope. Treat prospectivity and density as ranking tools, MRDS as frozen history, and the land layers as the gate. The map narrows where to look; the field decides. Verify land status with BLM and on the ground before entering or staking — decision-support, not legal advice.