About the data

Thirteen counties, whole: Yates, Steuben, Ontario, Schuyler, Seneca, Chemung, Cayuga, Tompkins, Livingston, Cortland, Onondaga, Wayne and Tioga — between them both shores of all eleven Finger Lakes (Conesus, Hemlock, Canadice, Honeoye, Canandaigua, Keuka, Seneca, Cayuga, Owasco, Skaneateles and Otisco), plus Waneta and Lamoka, reaching north to the Lake Ontario shore in Wayne and south to the Susquehanna in Tioga, and the towns among them: Penn Yan, Hammondsport, Bath, Corning, Painted Post, Campbell, Watkins Glen, Geneva, Canandaigua, Naples, Elmira, Aurora, Ithaca, Skaneateles, Auburn, Palmyra, Sodus, Owego and Candor. Everything comes from public sources and is refreshed from them, not entered by hand.

• Ownership, values, lot and building details — New York State ITS Geospatial Services and the NYS Department of Taxation & Finance (ORPTS), NYS Tax Parcel Centroid Points, from the counties' assessment rolls.
• Parcel boundaries — ten of the thirteen counties released theirs through the state — Steuben, Ontario, Schuyler, Cayuga, Tompkins, Livingston, Cortland, Onondaga, Wayne and Tioga — and come from NYS Tax Parcels Public. The other three publish their own and are pulled from the county directly: Yates (Real Property Tax Service's Parcel Viewer layer — a roll newer than the state file, so a few lots show as "new" with fewer details; last sale, stories and fire district come from it too), Chemung (the layer behind the county Parcel Viewer, the 2024 roll — a year older than the state attributes, so it supplies the outline only), and Seneca (the county's own parcel service, roughly a 2024 roll, outline only). Records with no mapped boundary — utility and franchise entries, and lots created since a county's roll — appear as pins.
• Tax estimates — published county, town and school rates from data.ny.gov, multiplied by the parcel's value. They are estimates: no exemptions (STAR, senior, veterans, agricultural), no special districts (fire, library, water) and no village taxes. The official bill is on the county's site.
• Aerial views — New York State's public orthoimagery program.
• Basemap & lake outlines — © OpenStreetMap contributors, tiles by OpenFreeMap. Lake outlines for Keuka, Seneca, Canandaigua, Cayuga, Waneta, Lamoka, Honeoye, Canadice and Hemlock.

Caution. Tax maps are reference material only and should never be used for actual property boundary determination. "Lakefront" flags are computed from map geometry and are approximate — especially for pin-only parcels.