Markline: Benchmark Hunting

Rizk Corsight, LLC

About this app

Markline is the offline field companion for benchmark hunting - the hobby of finding the brass disks, rods, and survey marks the government placed across the country.

Every U.S. survey mark from the National Geodetic Survey is bundled right in the app, so the whole catalog works with no signal, no account, and nothing uploaded.

WHAT YOU GET
- 795,000+ NGS survey marks, bundled for fully offline field reference
- A distance-sorted Nearby list: the closest marks to you, color-coded by their last reported condition, with a Hide-found toggle
- The complete datasheet for every mark: type, setting, coordinates, elevation, datum, stability, satellite use, and recovery history
- Browse by state and county, or search instantly by PID or designation
- Log your recoveries: found, not found, or destroyed, with a photo, condition, and note
- Track your progress across logged marks, found marks, and states
- Open any mark in your maps app for turn-by-turn directions, or download its full NGS datasheet once and keep it offline

WHO IT'S FOR
Benchmark hunters, geocachers, surveyors, hikers, and anyone curious about the geodetic control network hiding in plain sight.

PRIVACY
Markline collects nothing. There's no account, no tracking, and no ads. Your recoveries, notes, and photo references stay on your device. Your location is used only on-device to show nearby marks - it is never uploaded.

DATA SOURCE
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.

Markline v1 covers the United States and its territories.

What’s new

Bug fixes