This project creates an interactive GIS tool that shows which agencies manage hiking trail segments across San Diego County. Trail data from OpenStreetMap is spatially joined with land ownership data to reveal how trails cross federal, state, local, and non-profit lands.
The goal of this project is to provide an easy-to-use way to visualize trail ownership and management responsibility. Trails often feel seamless to users, but management can change multiple times along a single route. This project makes those boundaries visible.
San Diego County Boundary (San Diego County GIS)
California Land Ownership Dataset (California State Geoportal)
Trail data from OpenStreetMap accessed using OSMnx
Reprojected all data to WGS84 (EPSG:4326) for compatibility with OpenStreetMap and Folium
Clipped statewide land ownership data to San Diego County
Retrieved trail data from OpenStreetMap using a tiled grid approach to avoid query limits
Converted OSM network data to line features
Spatially joined trail segments with land ownership polygons
Classified trails by ownership level, group, and agency
Visualized results using static maps and an interactive Folium web map
Python, GeoPandas, OSMnx, Folium, Shapely, Pandas, NumPy, Matplotlib
Interactive web map showing trail ownership by agency
Static maps of land ownership patterns
Exported trail shapefile for reuse
Understanding who manages trail systems is important for recreation planning, land stewardship, and transparency. This project highlights the shared responsibility involved in maintaining public trail networks.