Map Beast

Coverage explorer →

About Map Beast

Map Beast is a personal browser for historical maps and aerial imagery — thousands of georeferenced layers (old atlases, Sanborn fire-insurance maps, USGS topo quads, and decades of aerial photography) overlaid on a modern basemap so you can see how a place has changed over time.

Source code and pipeline tooling: github.com/benoc617/mapbeast

What the layers are

  • Reference — modern basemaps (OpenStreetMap, Esri imagery) for orientation and comparison.
  • Imagery — historic and recent aerial photography: county/state ortho programs, USGS flights, and self-hosted mosaics, typically one representative year per decade.
  • Historical — scanned historic maps: USGS topographic quads back to the 1880s, city plat atlases (Bromley, Hopkins, …), Sanborn fire-insurance maps, and other georeferenced scans.

Under the hood a layer is either a self-hosted Cloud-Optimized GeoTIFF (scans we georeferenced and converted ourselves, streamed by byte-range straight from storage), a public tile service (state/federal GIS endpoints), or an ArcGIS dynamic service rendered per-tile on demand.

How the viewer works

  • The layer list shows what's relevant to your current viewport — pan/zoom and it updates. Check "Show all layers" to escape the filter, or use the layer search.
  • Up to two layers can be active at once. Adjust each layer's opacity with its slider, or switch to Side-by-side mode to compare them with a swipe divider.
  • Use the place search to jump anywhere (city, address, or lat, lon).
  • The URL always encodes your view and active layers — Copy permalink gives you a shareable link that restores exactly what you're looking at.

Coverage explorer

The Coverage explorer is a second page that answers "what's in here, and where?" It shows a US map of coverage dots — the density of layer footprints for the selected tab — plus a filterable, sortable table of every catalog layer, split into Aerial / Historic Map / USGS Topo tabs with year and resolution filters. Clicking a dot or a table row opens the viewer centered on that area or layer.