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research-plan.md

Historical Property & Area Research Plan

A methodology for creating a rich, compelling historical report on a home and its surrounding area using publicly available geographic data, satellite imagery, historical maps, and archival records.

Overview

Given a GeoJSON file containing a home location (point) and area of interest (bounding box polygon), this plan outlines how to research and compile a comprehensive historical report with linked imagery and maps.

Data Sources

Satellite & Aerial Imagery

Source Provider Access Notes
Current satellite imagery ESRI World Imagery Free, no API key High-res export via REST API. Multiple zoom levels recommended (wide context + close-up).
NAIP aerial photography USGS / USDA Free, no API key 0.6m resolution, 4-band, updated every 2 years
Historical satellite (2014+) ESRI Wayback Free Browse satellite imagery by date
Historical aerial photos (1930s+) USGS EarthExplorer Free account required Single-frame aerial photos
Historical aerials (~1885+) HistoricAerials.com Free preview (watermarked) Purchasable full resolution. URL: historicaerials.com/location/{lat}/{lon}/{year}/{zoom}
Regional aerial imagery (2002+) DRCOG (Denver region) / local MPOs Free Check your regional council of governments for free downloads
Street-level imagery Mapillary Free (OAuth token) Crowdsourced ground-level photos. URL: mapillary.com/app/?lat={lat}&lng={lon}&z=15
Street-level imagery KartaView Free Alternative to Mapillary. URL: kartaview.org/map/

Elevation, Terrain & LiDAR

Source Provider Access Notes
LiDAR hillshade USGS 3DEP Free, no API key Bare-earth terrain with buildings/vegetation stripped. Reveals drainage channels, ridges, and subtle landforms.
Raw elevation data USGS 3DEP Free, no API key Grayscale elevation raster. Light = higher, dark = lower.

Environmental & Land Classification

Source Provider Access Notes
Land cover classification USGS MRLC / NLCD 2021 Free, no API key Color-coded land use (residential, commercial, water, open space). Shows how land has been transformed.
Soil survey (SSURGO) USDA NRCS Free, no API key Soil mapping units with drainage, permeability, shrink-swell data. Lookup details in Web Soil Survey.
Flood zones FEMA NFHL Free, no API key Regulatory floodplain delineation. Zone AE = 1% annual flood chance.
Wetlands (NWI) USFWS Free, no API key Wetland boundaries — lacustrine, palustrine, riparian.
Hydrology (NHD) USGS Free, no API key Streams, rivers, canals, ditches, reservoirs. Often labels historic irrigation ditches by name.

Historical Maps

Source Provider Access Notes
USGS Historical Topo Maps USGS TopoView Free Decades of coverage in GeoPDF/GeoTIFF/JPEG. Use TNM API for programmatic search.
General Land Office surveys BLM GLO Records Free Original survey plats, land patents, homestead records
Historical maps collection David Rumsey Map Collection Free Thousands of georeferenced historical maps. Overlay viewer at rumsey.geogarage.com
State/local historical maps State historical societies Varies Often digitized and searchable online

Modern Reference Maps

Source Provider Access Notes
ESRI World Street Map ESRI Free, no API key Detailed labeled street map
ESRI World Topo Map ESRI Free, no API key Modern styled topographic basemap
USGS Topo Map USGS National Map Free, no API key Current official USGS topo
USGS Imagery+Topo Hybrid USGS National Map Free, no API key Satellite imagery with topo labels overlaid — excellent for orientation
OpenStreetMap OSM Contributors Free, no API key Community-maintained street map tiles

Property & Land Records

Source Provider Access Notes
County GIS / parcel data County assessor Usually free Property boundaries, zoning, ownership. Search "[County] GIS" or "[County] open data"
County assessor search County assessor Usually free Search by address, owner, parcel ID, or subdivision
County clerk/recorder County clerk Usually free Scanned deed and title records (often from 1950s forward)
City subdivision search City planning dept Usually free Look up subdivision plat names
Geological maps USGS Free Formation data, soil types. Search by quadrangle name.
Census data US Census Bureau Free Historical population and demographics
Radon risk EPA Free Radon zone maps by county. URL: epa.gov/radon/epa-map-radon-zones-and-supplemental-information

Archival & Historical Research

Source Type Notes
State historical society Photos, maps, documents Often 1M+ items digitized. Search by city/county name.
Public library digital collections Photos, newspapers, maps Local history departments are goldmines. Check for aerial photo collections.
University libraries Aerial photo archives, special collections Often have unique local coverage not available elsewhere
Library of Congress Maps, photos, newspapers Comprehensive digital collections
Getty Images Historical society photo collections Search "[City] Historical Society" — often 50-100+ photos available
Local historical society Local history, oral histories, events Often have websites, Facebook pages, monthly events
NRHP nominations Detailed building/area histories Available as PDFs from state historic preservation offices. Extremely detailed.
Newspaper archives Historical articles, event coverage Chronicling America (LOC) for pre-1963; state digital newspaper projects for later
eBird hotspots Bird species lists by location Excellent for documenting local ecology. URL: ebird.org/hotspot/{id}

Environmental & Ecological

Source Provider Access Notes
Wildlife refuges USFWS Free Refuge descriptions, species lists, management plans
Biological inventories State natural heritage programs Often free PDFs Detailed species and habitat surveys for specific areas
Superfund sites EPA Free Search "Superfund sites where you live" for nearby contamination
State environmental health State DPHE Free Site-specific contamination info, cleanup status
Trail information American Trails, AllTrails Free Trail maps, designations, descriptions

API Endpoints for Image Downloads

These URL patterns work with any bounding box (replace {bbox} with west,south,east,north in EPSG:4326):

# === SATELLITE & AERIAL ===

# ESRI World Imagery (current satellite)
https://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/export?bbox={bbox}&bboxSR=4326&size=1200,1200&imageSR=4326&format=jpg&f=image

# USGS NAIP Plus (aerial photography)
https://imagery.nationalmap.gov/arcgis/rest/services/USGSNAIPPlus/ImageServer/exportImage?bbox={bbox}&bboxSR=4326&size=1200,1200&imageSR=4326&format=jpg&f=image

# === ELEVATION & TERRAIN ===

# USGS 3DEP Hillshade (bare-earth LiDAR terrain)
https://elevation.nationalmap.gov/arcgis/rest/services/3DEPElevation/ImageServer/exportImage?bbox={bbox}&bboxSR=4326&size=1200,1200&imageSR=4326&format=jpg&renderingRule={"rasterFunction":"Hillshade Gray"}&f=image

# USGS 3DEP Elevation (raw grayscale elevation)
https://elevation.nationalmap.gov/arcgis/rest/services/3DEPElevation/ImageServer/exportImage?bbox={bbox}&bboxSR=4326&size=1200,1200&imageSR=4326&format=jpg&f=image

# === ENVIRONMENTAL LAYERS ===

# NLCD 2021 Land Cover (color-coded land use classification)
https://www.mrlc.gov/geoserver/mrlc_display/NLCD_2021_Land_Cover_L48/wms?service=WMS&version=1.1.0&request=GetMap&layers=NLCD_2021_Land_Cover_L48&bbox={bbox}&width=1200&height=1200&srs=EPSG:4326&format=image/png

# SSURGO Soil Map (USDA NRCS soil survey units)
https://sdmdataaccess.nrcs.usda.gov/Spatial/SDM.wms?SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&LAYERS=MapunitPoly&STYLES=&SRS=EPSG:4326&BBOX={bbox}&WIDTH=1200&HEIGHT=1200&FORMAT=image/png

# FEMA Flood Zones (all layers)
https://hazards.fema.gov/arcgis/rest/services/public/NFHL/MapServer/export?bbox={bbox}&bboxSR=4326&size=1200,1200&imageSR=4326&format=png&transparent=false&f=image

# NWI Wetlands (USFWS via USGS WIM)
https://fwsprimary.wim.usgs.gov/server/rest/services/Wetlands/MapServer/export?bbox={bbox}&bboxSR=4326&size=1200,1200&imageSR=4326&format=png&transparent=false&f=image

# NHD Hydrology (streams, canals, water features)
https://hydro.nationalmap.gov/arcgis/rest/services/nhd/MapServer/export?bbox={bbox}&bboxSR=4326&size=1200,1200&imageSR=4326&format=png&transparent=false&f=image

# === REFERENCE MAPS ===

# ESRI World Street Map
https://services.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer/export?bbox={bbox}&bboxSR=4326&size=1200,1200&imageSR=4326&format=jpg&f=image

# ESRI World Topo Map
https://services.arcgisonline.com/ArcGIS/rest/services/World_Topo_Map/MapServer/export?bbox={bbox}&bboxSR=4326&size=1200,1200&imageSR=4326&format=jpg&f=image

# USGS Imagery + Topo Hybrid (satellite with labels)
https://basemap.nationalmap.gov/arcgis/rest/services/USGSImageryTopo/MapServer/export?bbox={bbox}&bboxSR=4326&size=1200,1200&imageSR=4326&format=jpg&f=image

# USGS Current Topo Map
https://basemap.nationalmap.gov/arcgis/rest/services/USGSTopo/MapServer/export?bbox={bbox}&bboxSR=4326&size=1200,1200&imageSR=4326&format=jpg&f=image

# OpenStreetMap (street map tiles, zoom/x/y format)
https://tile.openstreetmap.org/{z}/{x}/{y}.png

# === HISTORICAL MAPS ===

# USGS Historical Topo Maps (search API — returns JSON with download URLs)
https://tnmaccess.nationalmap.gov/api/v1/products?datasets=Historical%20Topographic%20Maps&bbox={bbox}&max=50&outputFormat=JSON

# Same query filtered to GeoTIFF/JPEG formats
https://tnmaccess.nationalmap.gov/api/v1/products?datasets=Historical%20Topographic%20Maps&bbox={bbox}&max=50&outputFormat=JSON&prodFormats=GeoTIFF,JPEG

Notes on API Endpoints

  • All ESRI, USGS, FEMA, NRCS, and USFWS endpoints are free and require no API key
  • The size=1200,1200 parameter controls output resolution — increase for higher quality
  • The f=image parameter returns raw image bytes (save directly with curl)
  • Change f=image to f=json on ESRI endpoints to get metadata instead
  • NLCD tree canopy layer (L48) is not available via WMS — only Alaska, Hawaii, and Puerto Rico layers exist
  • FEMA endpoints use /arcgis/ path prefix: hazards.fema.gov/arcgis/rest/...
  • For close-up views, compute a tighter bbox around the point of interest (e.g., +/- 0.002 degrees)
  • For wide context views, use a much larger bbox (e.g., +/- 0.15 degrees)

Report Structure

1. The Land — Geography, Geology & Environment

  • Underlying geological formations and soil types
  • Waterways, elevation, terrain (hillshade + elevation images)
  • Soil survey data and what it reveals about the land's history
  • Environmental concerns (radon, contamination, flood risk)
  • Original native ecosystem and vegetation
  • Sources: USGS geological maps, 3DEP elevation, NRCS soil surveys, FEMA flood maps, NHD hydrology

2. First Peoples

  • Indigenous nations who called the area home
  • Archaeological evidence and oral histories
  • How the land was used pre-contact
  • Sources: State historical society, tribal histories, academic research

3. Settlement & Homesteading

  • How and when Euro-American settlement began
  • GLO survey records: township, range, section
  • Original land patent holders and homesteaders
  • Early infrastructure: irrigation ditches, roads, buildings
  • NRHP-listed structures and their nomination documents
  • Sources: BLM GLO Records, county archives, historical topo maps, NRHP nominations

4. Agricultural & Economic Development

  • What was grown or produced on the land
  • Economic drivers and industries (farming, mining, manufacturing)
  • Growth of towns and communities
  • Neighborhood-specific development stories
  • Sources: Census records, local histories, newspaper archives, land cover data

5. Modern Development

  • Suburbanization and residential growth
  • Municipal incorporation and governance
  • Significant events (floods, fires, economic shifts)
  • Close-up satellite showing current neighborhood character
  • Home construction dates and subdivision history
  • Sources: NAIP imagery, ESRI Wayback, census data, county assessor records

6. The Area Today

  • Current character, demographics, landmarks
  • Parks, greenways, preserved natural areas
  • Wildlife and ecology (eBird data, biological inventories)
  • Commercial corridors and community identity
  • Environmental concerns (Superfund sites, contamination, radon)
  • Sources: Current satellite imagery, county GIS, census, USFWS, eBird

7. Reading the Maps

  • Annotated current maps (imagery+topo hybrid, USGS topo, street map)
  • Historical topo map series with descriptions of what changed between editions
  • Links to interactive viewers (TopoView, Wayback, HistoricAerials.com)

8. Timeline

  • Chronological table from geological time through present day
  • Key dates for the specific area

9. Sources & Further Reading

  • Interactive map links
  • Property and land record portals
  • Archive and historical collection links
  • Ecological and environmental references
  • Image inventory table with filenames, descriptions, and sources

Deliverables

  • report.md — Main narrative report with embedded image references
  • images/ — Directory of downloaded satellite, aerial, environmental, and map images (expect 20+ files, ~40MB)
  • home.geojson — Original location data
  • research-plan.md — This methodology document (shareable)

Recommended Image Set

Download at minimum these layers for any property report:

Priority Image Why
Essential Satellite (area) Primary visual anchor
Essential Satellite (close-up of home) Shows the immediate neighborhood
Essential Satellite (wide context) Shows regional setting
Essential NAIP aerial Higher quality than satellite, shows vegetation detail
Essential Historical topo maps (3-4 editions) Shows transformation over time
High LiDAR hillshade Reveals hidden terrain features
High FEMA flood zones Flood risk context
High NHD hydrology Streams, ditches, water features with labels
High USGS Imagery+Topo hybrid Best single reference map
Medium NLCD land cover Land use classification
Medium SSURGO soil map Soil types and agricultural potential
Medium NWI wetlands Wetland boundaries
Medium Elevation (raw) Topographic context
Medium Street map Road network reference
Medium Modern topo map Current USGS or ESRI topo
Optional OpenStreetMap tile Community-maintained alternative

Determining Township/Range/Section

To find the GLO survey coordinates for any US location:

  1. Use https://www.randymajors.org/township-range-on-google-maps to look up T/R/S from lat/lon
  2. Search https://glorecords.blm.gov/ with the T/R/S values to find original patents
  3. Look for homestead entries, cash entries, and military bounty land warrants

Research Tips

Finding Images & Maps

  • County GIS portals often have the richest local data — search for "[County Name] GIS" or "[County Name] open data"
  • State universities often maintain aerial photo archives not available elsewhere
  • USGS TopoView shows the same area across decades — invaluable for seeing development over time
  • The ESRI Wayback viewer lets you scrub through satellite imagery year by year since 2014
  • HistoricAerials.com has coverage back to ~1885 for many US locations
  • Denver Public Library (and equivalents in other cities) often have aerial photo collections from the 1920s-1930s
  • Getty Images often has historical society photo collections searchable by city name

Finding History

  • NRHP nomination documents are the single best source for detailed local history — they're free PDFs with extensive research
  • Historical newspapers via Chronicling America (LOC) or state digital newspaper projects often have articles about specific properties
  • Local historical societies often have websites, Facebook pages, and monthly events
  • County archives may have digitized records (deeds, plats, photos) going back to the 1800s
  • Search for "[City] history" on WordPress/Blogspot — local history enthusiasts often maintain detailed blogs
  • eBird hotspot data provides excellent ecological documentation for any location with birding activity

Technical Tips

  • For close-up satellite views, use a bbox of approximately +/- 0.002 degrees around the point
  • For wide context, use +/- 0.15 degrees
  • Always verify downloaded images are valid (check file size > 1KB; very small files are usually error responses)
  • PDFs and GeoTIFFs won't render inline in markdown — link to them instead of embedding
  • JPG and PNG images render inline in most markdown viewers
  • The TNM API (for historical topos) can be slow — retry on timeout
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