Map Layers

Every layer in the app, what it shows you, and where it covers.

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Ultra 1m LiDAR

Pro

See the ground with the trees taken off

A bare earth hillshade built from USGS 3DEP one-meter lidar. It removes the canopy and leaves the shape of the dirt behind, so old placer cuts, hydraulic pits, tailings piles, ditch lines and benches read as forms you can recognize, on hillsides no aerial photo can see into.

  • Lit from every side. The hillshade is lit so linear features like ditch lines and water races show whichever way they run, rather than flattening into shadow on a slope that faces the wrong way.
  • Not just lidar. Our own recipe. Plenty of apps show a lidar hillshade. Ultra 1m is processed with our own blend of multi-angle shading, local-relief enhancement and sharpening, tuned specifically to bring out the subtle, man-made ground prospectors and detectorists hunt for: tailings piles, ditch lines, hydraulic cuts and old benches, with detail all the way in.

Coverage California, Oregon, Washington, Idaho, Nevada and Arizona, with more states on the way. It draws only where one-meter data exists and is blank elsewhere.

Updated daily

Pro

BLM active and closed claims

Over 500,000 active claims across the United States and more than 80,000 closed claims, refreshed daily.

Active claims tell you whether the ground is already spoken for before you dig. Closed claims tell you where somebody once thought it was worth filing on, which is a lead in itself.

Coverage The entire United States.

A scanned historic USGS topographic sheet drawn over the map, with the era band picker open showing the oldest, classic and detailed options

Sheets back to 1879

Pro

Read the maps drawn while the ground was still working

Scanned USGS sheets going back to 1879 carry mines, ditches, camps, mills and roads that appear on no modern map. What was worth drawing then is usually still in the dirt now, just grown over. Three era bands toggle independently, so you can step through time on a single spot.

  • Three era bands. Grouped by map scale at 24k, 62k and 125k, each switched on and off on its own.
  • Compare across decades. One band at a time shows what stood on a spot in the 1890s against what stood there in the 1940s.
  • Opacity you control. Fade a historic sheet over satellite imagery to line an old ditch up against present-day terrain.

Coverage The entire lower 48.

529,547 worked sites

Pro

Every mine somebody bothered to write down

529,547 worked sites from the USGS mine records and the mine symbols on USGS topo sheets, with a pin for each kind of working. Each one carries a name, the commodity, the deposit type and the development status.

  • Producer or prospect hole. Development status separates a documented producer from a hole somebody scratched at once and walked away from.
  • Placer or lode. Deposit type tells you how a site was worked before you spend a morning driving to it.
  • Adits, shafts and dumps. The topo-sheet symbols bring in the physical workings somebody drew because they were visibly there, not just the ones that got filed.

Coverage The United States.

Parcel boundaries drawn over satellite imagery on rural ground west of Redding, California, with individual lots and their access roads clearly separated

2,000+ counties

Pro

Know where public ground ends

Parcel boundaries sit over the map so the line between public and private is one you can actually see. Tap a parcel and it opens what the county publishes about it. The difference between asking permission and trespassing is usually one boundary nobody fenced.

  • Tap for the details. A parcel returns its assessor parcel number, the address and the acreage.
  • Owner names vary by county. Some counties have owner information and some do not.

Coverage 2,000+ counties across the lower 48.

Public land unit boundaries near Keswick, California, color coded by managing agency, with a unit detail open showing that the area is open to public access and managed by the Bureau of Reclamation

Per-unit boundaries

Pro

Public does not always mean open

Land status is drawn unit by unit rather than as one undifferentiated block of federal ground. Three separate toggles cover who holds the ground and what has been laid on top of it. Who owns a piece of land will not on its own tell you whether you are allowed to prospect it.

  • Who holds the ground. Federal, state and local land is drawn as boundaries, each one named and colored by the agency that manages it.
  • What sits on top of it. Wilderness areas, monuments and similar restricted designations toggle on their own and can close ground that looks open underneath.
  • Whether you can walk in. Each unit says whether it is open to public access, which is the part that decides your weekend.

Coverage The United States.

A creek traced across bare earth lidar with its detail sheet open, naming the creek, its flow regime, its size class and its average annual flow in cubic feet per second

Tap any waterway

Pro

Sort the live drainages from the dead ones

Every mapped waterway, drawn from the USGS National Hydrography Dataset. That includes the small feeders and seasonal channels that never make it onto a road map, which are usually the ones worth walking.

Tap a waterway and it identifies itself

You get its name, whether it runs year round, only in season or only after rain, its size class, and its average annual flow in cubic feet per second.

  • Most washes are dry when you stand in them. Knowing whether a channel is a perennial creek that dropped, a seasonal drainage or pure storm runoff tells you what kind of deposit to expect and where the material came to rest.
  • Work it out before you drive. For dry washing, and for detecting dry creek beds, live and dead drainages sort at the kitchen table instead of costing a day in the field.

Coverage The United States.

Shasta Lake seen in tilted 3D over satellite imagery, with stream and river channels drawn through the reservoir pool and up each of its arms

Channels drawn through the pool

Pro

Know where the old bed lies when the water drops

Lakes, ponds and reservoirs drawn from the USGS National Hydrography Dataset. Tap one for its name, its surface acreage and what kind of water body it is.

  • The river is still under there. Where a channel runs through a reservoir the channel is drawn in, so when the pool drops in late summer you know where the original bed sits rather than guessing at a shoreline.

Coverage The United States.

Researched on demand

Pro

Find the places the maps stopped drawing.

Historical towns, camps, homesteads, post offices and forts from the USGS place-name record, each with a pin by type.

  • Tell me more. Tap a place and hit Tell me more. Gold Prospector researches it and writes the history onto the card: when it was active, what it was for, why it ended and what is left.
  • It finds you when it is done. A banner lets you know the research is ready even if you have moved on, and once a place is researched the card opens instantly.

Coverage The lower 48.

NPS and the National Register

Pro

Battlefields, mills and the buildings that are left.

National Park Service battlefields, with the core shaded and the study area outlined, alongside National Register of Historic Places buildings, districts, mills and towns.

  • Where people actually were. Where people lived and worked is where relics, coins and old workings turn up.
  • Works offline. The layer comes down with a downloaded area like the rest.

Coverage The lower 48.

Pre-1911 grades

Pro

Walk the grades the railroads left behind.

Pre-1911 rail grades with their stations, sidings and stops. Tap a line for the company and the year.

  • A grade goes somewhere. An old grade is a road straight to a camp or a mine that no longer shows on a modern map.

Coverage The lower 48.

2016 onward

Pro

See the ground a fire just opened up.

Wildfire burn scars from 2016 on, drawn from MTBS, NIFC and CAL FIRE.

  • Age at a glance, severity up close. Zoomed out the color shows how old the burn is. Zoomed in it shows how hard it burned.
  • It tells you the window. Each burn gives a read on how much regrowth to expect, which is what decides how long the ground stays open to work.

Coverage The lower 48.

What came out of the ground

Pro

Every USGS deposit, colored by what was in it.

USGS deposit records across the country, each marked and colored by its main commodity, so a district's gold, silver, copper and lead show at a glance.

  • Producer or prospect. Solid marks are past producers and dashed marks are prospects, so you can tell where ore was actually mined.
  • Tap for the detail. A deposit returns its commodities, ore minerals and production size.
  • Metals stay readable. Industrial minerals are hidden by default, so a metal district is not buried under sand and gravel pits.

Coverage Nationwide.

310,000+ sheets · 1879 to 1930

Pro

Lay an old town map over the ground it was drawn for.

310,000+ historic town and city maps from 1879 to 1930, showing every building, mill and street as it stood.

  • Place it yourself. Search near you or by name, place a sheet over the modern map, and switch between editions.
  • Placed once, placed for everyone. Placed maps are shared, so every one you add helps the next person.

Coverage The lower 48.

Modeled gold potential

Pro

Know which stretch is worth the walk.

Gold potential shaded in three tiers (Best, Better, Good), scored from stream-sediment geochemistry, the density of historic mine workings, bedrock and placer settings, and ranked within each state so the best ground stands out.

  • See the reasoning. Tap any zone to see why it scored.
  • Ranked within a state. The tiers are relative, so Best means best in that state rather than best in the country.
  • A model, not a guarantee. It is built from real data but it is still a model, so use it to decide where to spend a day.

Coverage California, Nevada, Arizona, Oregon, Washington, Idaho, Colorado, Montana, Utah, New Mexico, Wyoming, South Dakota, North Carolina, South Carolina, Georgia, Virginia, Alabama, Maine, Vermont and New Hampshire.

Where heavy gold settles

Pro

Inside bends and gully mouths, marked for you.

Points computed from the terrain at creek bends and steep-gully runoffs near known gold occurrences: the places moving water slows down and drops what it was carrying.

  • Where the flow changes. Each point is a spot where water changes speed or direction, which is where heavy material comes to rest.
  • Only near documented gold. Points are placed near known occurrences, so the layer is not marking every bend in the country.
  • A model, not a promise. Treat each point as a reason to look rather than something already proven.

Coverage California, Nevada, Arizona, Oregon, Washington, Idaho and Colorado.

Know before you drive in

Pro

Every road and trail, and who runs it.

Roads and trails from the USGS, Forest Service and BLM in one layer, so you can see how to get in, and whether you are allowed to, before you leave pavement.

  • Tap any route. It returns the name, number, surface, managing agency, vehicle class and any seasonal closures.
  • Old roads stay on the map. Closed and decommissioned roads are kept, because an old road is often the way to an old working.
  • Off-road trails on their own switch. OpenStreetMap off-road trails are separate, so they do not clutter the agency routes.

Coverage Lower 48. Works offline.

The rest of the stack

Four more layers that answer the second question rather than the first.

Terrain and access

  • USGS Topo Contours

    The current topographic basemap, and the reference the scanned historic sheets get compared against.

  • Rock Types

    Surface geology units, where a contact, a fault or the right intrusive decides whether ground is worth the walk.

Mineral data

  • Geochemistry

    Stream-sediment, soil, rock and pan-concentrate samples with the full assay, colored by gold tier. Downloads for offline use like the other layers.

  • Magnetic Anomaly

    Aeromagnetic survey data, reading the buried contacts, intrusives and fault zones the surface does not show. The one layer that does not download for offline use.

Free My Pins and Find Log Pins, logging finds and recording tracks, the Community, Messages, Tips & News and your profile are free. Every map layer is Pro, and a 7-day free trial unlocks everything first.

Every layer above is credited agency by agency and county by county on the data sources page.