Show HN: Unfenced – Land for sale that borders public land

Unfenced is a searchable mapping tool that identifies private parcels which directly border public lands - national forests, wildlife management areas, game lands and wilderness - by measuring official boundary data rather than relying on listing descriptions. Users can browse by state or open an interactive map to see measured shared boundaries, acreage, prices and parcel locations, with an emphasis on properties that offer immediate access to contiguous public open space. The project’s tagline, “Walk out the back door. Keep going,” reflects its purpose: help buyers find land with direct, mapped adjacency to public land for recreation, hunting, or conservation-minded ownership.

The database reports 13,626 measured properties, derived from a search of 695,439 active listings and checked against USGS PAD‑US 4.1 and other public boundary datasets; coverage spans 49 regions (no current results for DC or North Dakota) and updates roughly weekly. Example listings show measured shared-boundary lengths in feet alongside acreage and asking price (e.g., a 120‑acre Oregon parcel with 5,240 ft of shared boundary). Results note important limitations: measurements are based on public data and are not a legal survey or a substitute for professional title and boundary verification, and the project is maintained by Other Waters Studio in Philadelphia.