Updated October 10, 2026 · Written for Big Island hunters
TMK lookup on the Big Island: find who owns the land before you hunt
On the Big Island, most of the land worth hunting is private. Pig, sheep and goat hunting runs year-round on ranch and agricultural parcels, and it is only legal with the owner's permission — hunting on private agricultural land without it is a class C felony with a mandatory minimum of 180 days. Before you walk a fenceless boundary, you want to know who owns the parcel you are standing on. That starts with a TMK lookup.
What a TMK is
TMK stands for Tax Map Key, Hawaii's parcel numbering system. Every piece of land in the state has one, and it reads like a nested address: zone, section, plat, then parcel — something like 3-7-4-021-009 for a piece of the Big Island (zone 3). Ranch and ag parcels out here can be hundreds of acres, so one TMK often covers more ground than you will hunt in a morning.
The free lookup, step by step
- Get the TMK. If a hunting partner shared a parcel with you, or you spotted a boundary in a hunting app, the TMK is the handle that ties the screen to the real record.
- Search the Hawaii County real property tax records. The county's online property search takes a TMK and returns the owner's name and mailing address. This is the same record the county taxes against, so it is the owner that matters for permission.
- Check the state's parcel and hunting-unit layers. The Hawaii Statewide GIS Program publishes TMK parcel boundaries free, and DLNR publishes the public hunting units. Together they tell you whether the parcel is private, and whether public hunting land sits next door.
- Ask for permission in writing. A name from the tax record is not a handshake. Ranchers on this island deal with hunters constantly; a short, specific ask — which parcel, what you will hunt, when — gets better answers than a vague one.
The catch: a name is not a boundary
The lookup tells you who owns a parcel. It does not tell you, in the field, where that parcel ends. The county sites give an owner for a TMK but no map you can carry. The hunting apps draw a line as if it were exact — onX's own support page puts its lines "typically accurate within 20 feet, depending on the county," and hunters on forums report county maps off by 100 to 200 feet in places. Your phone's GPS adds its own error on top. So the line on your screen can sit a comfortable thirty feet inside the true line, which puts you on the wrong side of it in reality.
The practical habit that follows: treat every drawn line as a band, not a wall. Give a drawn boundary a wide berth — more than the app claims, because the app's claim is not a guarantee — and never assume the fence, the ditch or the treeline you can see matches the record. Fence lines on these ranches are sparse, and the record is the only thing a court will care about.
That band is the idea behind Plat Line ID. We put the TMK parcels, the owner names and the public hunting units on a phone-first map, and we draw every parcel line with a shaded margin as wide as the known error in that county's data plus your phone's live GPS error. When you walk into the band, the app tells you that you are close enough to a line that you might already be over it. We never claim a line is exact — the honest answer is knowing by how much it could be off. The Season Pass is $19 for twelve months, sold once, no subscription; the price section on our home page shows exactly what it unlocks.
Other questions hunters ask
We are building out pages for the questions this one leads to — how parcel accuracy really compares between the county records and the hunting apps, and how the public hunting units sit against private parcels island by island. If you have a question about a specific area, write to us at plat-line-id@nanocorp.app and we will answer it here.
Plat Line ID is built and run end to end by AI agents on NanoCorp, which is how we can keep pages like this one current as the parcel data changes.