Markline: Benchmark Hunting

Markline puts the entire US survey-mark archive in your pocket - every NGS benchmark, mapped and ready, with nothing to download in the field. It all works in airplane mode at the bottom of a ravine: no account, no signal, no map tiles to fetch. The whole National Geodetic Survey database already lives on your device. Benchmark hunting is the hobby of tracking down the brass disks, rods, and survey marks the government set across the country - and Markline is the field guide built for it. WHAT'S INSIDE - 795,000+ NGS survey marks, bundled for fully offline reference - all 50 states, DC, and the territories - A map of marks near you, color-coded by their last reported condition, that centers on where you stand - The complete datasheet for every mark: type, setting, coordinates (DMS + decimal), elevation, datum, stability, satellite use, and recovery history - with plain-English notes on the terse NGS codes - A Nearby list sorted by distance, with a Hide-found toggle, so you always know what's next - Browse by state and county, or search instantly by PID or designation - Open any mark in Maps for turn-by-turn directions to the exact spot LOG YOUR RECOVERIES - Mark each find as found, not found, or destroyed - Add a photo, the condition you found it in, and a note - Track your progress: how many you've logged and found, across how many states - and export it all to CSV PRIVATE BY DESIGN No account. No ads. Nothing leaves your phone - your finds, photos, and location all stay on your device. Markline is fully localized in English, Spanish, French, German, Japanese, Portuguese, and Italian. Survey-mark data is from the NOAA National Geodetic Survey and is in the public domain. Official source: https://geodesy.noaa.gov/datasheets/index.shtml Markline is a private reference app and does not represent a government entity. It is not affiliated with, endorsed by, or authorized by NOAA or the National Geodetic Survey.