Map Explorer: Historic Maps, LiDAR, Claims and Gold Samples

Historic USGS maps by year. Pick any year from 1885 to 2005 and the explorer shows the nearest edition of the USGS topographic map for the area you are looking at, drawn from the full Historical Topographic Map Collection. Slide the see-through control to fade the old map over today's satellite photo and find stage stations, schools, churches, ranches, mills, mines, springs, wells and trails that are gone today.

Bare-earth LiDAR. In the United States the explorer draws USGS 3DEP elevation as multidirectional shading, which removes trees and brush so old roads, foundations, prospect pits, mine dumps, ditches and cellar holes show as shapes on the ground. Outside the United States it uses worldwide terrain shading, which is LiDAR-sharp in much of Europe, the United Kingdom, Australia and New Zealand.

Mining and prospecting layers. Turn on USGS recorded mines and prospects (gold sites in yellow, silver in white), active BLM mining claims with claim names and case numbers, and USGS stream-sediment samples linked to their lab results for gold, silver, arsenic and other pathfinder elements. Gold or pathfinders in a creek sample point upstream to the source; placer gold collects downstream in inside bends and on bedrock.

Land ownership. The land layer shows federal, state, tribal and private land from the BLM Surface Management Agency dataset, so you can see who manages a spot before you plan a trip. Boundaries are generalized; confirm on county parcel records and BLM records before any fieldwork.

Hand a spot to the AI research agents. Click any point and choose Prospect here, What used to be here, or Treasure stories near here. The research agents read the same maps and data plus old books, newspapers and USGS reports, and answer with sources, an evidence grade and search areas. Every quote and coordinate is checked against the sources before you see it.

How it compares. Layered map apps make you do the cross-referencing yourself. The Map Explorer gives you the layers for free and adds research agents that connect them to the written record. It does not show private landowner names, which come from paid county parcel data.