What Is PAD-US? The National Public Lands Dataset

PAD-US, the Protected Areas Database of the United States, is the national inventory of public lands and other protected areas, maintained by the U.S. Geological Survey through its Gap Analysis Project. It records where parks, forests, refuges and other lands are, who manages them, and how open they are to the public.

What PAD-US actually is

Think of PAD-US as the common reference layer behind many public-land maps. It combines boundaries and attributes from federal, state, local and some private conservation sources into one national dataset, maintained by the U.S. Geological Survey. Most people never download it directly. They see it as the shaded polygons on a map app that show where public land begins and ends.

The database is a compilation. Federal agencies, state agencies, local governments and conservation nonprofits report their lands, and the dataset is revised in periodic releases rather than continuously. That is why it is useful at national scale and also why it can disagree with a local agency’s own map.

What kinds of land it includes

• Federal lands: national forests, BLM lands, national parks, wildlife refuges, military lands and more
• State lands: state parks, state forests, wildlife management areas and state trust lands
• Local lands: county and city parks, open space and municipal preserves
• Private conservation lands: nonprofit preserves and land under conservation easements
• Other protected areas, including some tribal and special-designation lands depending on the data submitted

Not every acre listed is public in the sense of open for you to walk onto. Some are protected but closed to visitors, and a conservation easement may protect land that remains private property. Reading the attributes is what tells these apart.

The attributes that matter to you

Each polygon carries information beyond its shape. The exact field names are technical, but in plain terms these are the pieces most useful to an outdoor reader:

• Manager name and type. Which agency or organization runs the land, such as a federal agency, a state agency or a local government.
• Owner type. Who actually holds title, which may differ from who manages the site.
• Designation. The kind of unit, such as national forest, state park, wildlife area or wilderness.
• Public access status. A category, commonly open access, restricted access, closed or unknown.
• Acreage. The mapped size, which is an estimate and not a survey result.
• Protection status. A code describing how strongly an area is protected for biodiversity, which is not the same thing as how open it is to recreation.

The access field is the one people lean on most, and also the one most often misread. Open access generally means the land is available to the public with few or no restrictions, though fees, permits and seasonal closures can still apply. Restricted means access depends on a permit, a fee or other conditions. Unknown means the data source did not say.

What PAD-US is good for

Its biggest strength is scale. It lets you see, in one place, which blocks of land across a county, a state or a region are public, and who runs them. That makes it ideal for scouting, such as finding public tracts near a town you are visiting, spotting access points to a large forest, or checking whether a patchwork of parcels may offer a legal corridor.

• Finding candidate public land when you are starting from a blank map
• Learning who manages an area so you know whose rules to look up
• Seeing the overall shape of a forest, refuge or wildlife area, including inholdings
• Comparing public acreage across regions when planning a trip
• Pairing with other layers, such as trails and roads, to plan access

Hunters, anglers, foragers and campers use it the same way: as a first filter. Our guide to public-land hunting for beginners shows how to turn a candidate tract into an actual plan.

Limits you need to know about

PAD-US is a starting point, not a legal boundary survey. Several things can make it wrong or misleading on the ground.

• Generalized boundaries. Lines are drawn from varied sources and can be noticeably off from the true line on the ground. Near a property line, that margin matters.
• Data lag. Land is bought, sold, exchanged and reclassified every year, and a national dataset may not reflect last season’s change.
• Mixed ownership. Public land often contains private inholdings, and maps can miss small parcels.
• Access labels are coarse. Open does not tell you which activities are allowed. Hunting, camping, foraging, drones and vehicles can all have separate rules.
• Easements and rights of way. A conservation easement protects land without opening it. A public road may cross private land, and public land may be reachable only through private land.
• Gaps and errors. Some local lands are missing, mislabeled or only partly reported.

The practical rule is a two-source habit. A PAD-US-based map tells you where to look, and a second source, such as the managing agency’s own map or a posted sign, tells you whether you can act. When the two disagree, trust the one closer to the ground and the one that is more recent, and ask the agency if you are still unsure.

GPS adds its own error, particularly under tree cover or in canyons, so a blue dot sitting a few feet inside a boundary line is not proof you are on public land.

How maps and apps use PAD-US

Many public-land layers in outdoor apps draw on this dataset, often with their own styling and refresh schedule. On the WildPass Explore map and in the Android app, the public-land boundary overlay is built from USGS PAD-US; it appears once you zoom in, and you can tap a boundary to see details such as the manager and access status. See the WildPass app page for the Android app; iPhone users can use the website as an installable web app.

In the Android app, boundaries for areas you have already viewed with a connection stay available without cell service, separately from any offline map download. Treat the overlay as a planning aid, not a survey. Offline maps for hiking and hunting explains how to prepare before a trip.

A worked example, step by step

Say you are planning a fall weekend near a small town and want to know what public land is close. You open a layer built on PAD-US and see a large shaded block to the north, with a smaller block beside a lake to the east. The big block lists a federal forest agency as manager and shows open access. The small one lists the state and shows restricted access.

That is already useful. The forest tract is a candidate for dispersed camping or hiking, subject to the forest’s rules and any closures. The state tract may require a day-use fee, a permit or specific hours, and may prohibit overnight stays or gathering. Neither label answers whether your activity is allowed, so your next stop is each manager’s own website or office.

Then you look at how to reach each one. The forest block has a road along its southern edge. The state block appears to sit behind private farmland with no obvious entry. That tells you to look for a public road or recorded easement before planning a route, and to avoid cutting across someone’s field.

A practical way to use it

1. Find a likely tract on a PAD-US-based layer and note the manager.
2. Look up that manager’s official page or map for the area, and read the rules for your activity.
3. Cross-check ownership against a second source; how to tell if land is public or private shows the full method.
4. Confirm legal access: is there a public road, trail or easement to the boundary?
5. On the ground, look for agency signs, boundary markers and gates before you commit.

If you are new to the managers themselves, our comparison of national forest, BLM and state land compares how each one typically treats camping, fire and foraging. Once you have a candidate, browse state hubs for nearby places with details and costs.