Old Maps for Treasure and History Research
Verdict summary
Historic maps show what stood on the ground when a story happened: roads, stage stations, ranches, mines, springs and buildings that later maps drop. The most useful are early USGS topographic quads, General Land Office survey plats, Sanborn fire-insurance maps of towns, and old county and railroad maps. Laid over modern LiDAR and imagery, they show where to look today.
Map types.
USGS historical topographic maps (from the 1880s onward) show terrain, roads, trails, mines and buildings. GLO survey plats (from the 1800s) record section lines, early roads, cabins and fields. Sanborn maps (1867 to about 1970) show town buildings lot by lot. County, railroad and military maps add detail for their areas.
Combining old and new.
Georeferencing an old map onto modern imagery or 1-metre LiDAR shows whether a vanished road, building or trail left traces in the ground. LiDAR can reveal old road beds, foundations and diggings under vegetation.
How PinPoint Treasure helps.
Ask PinPoint Treasure about a specific place or story and it researches the records for you: newspapers, land and mining records, old maps, LiDAR and land status, with the source behind every claim. For any US point it lists the historical topo maps, oldest first, with downloads.
Where can I find old topographic maps? The USGS Historical Topographic Map Collection has scanned quads, many from the late 1800s and early 1900s. PinPoint Treasure lists the maps that cover any US point, oldest first.
What are Sanborn maps? Detailed fire-insurance maps of US towns, made from 1867 to about 1970, showing buildings lot by lot. The Library of Congress has a large digitized collection.