USGS 3DEP: U.S. Elevation, Lidar, and Terrain Data for GIS
USGS 3DEP, the U.S. Geological Survey’s 3D Elevation Program, is an open national framework for high-resolution elevation data across the United States and its territories. It combines lidar point clouds, seamless digital elevation models, source-resolution DEMs, contours, and Alaska IfSAR products distributed through The National Map. The program is particularly useful for terrain modeling, hydrology, flood and watershed analysis, infrastructure planning, landform interpretation, orthorectification, and geographic analysis that depends on elevation. 3DEP is not one uniform raster with a single acquisition date or resolution: product availability, source quality, acquisition vintage, vertical reference, and update status vary by location and product type.
The USGS 3D Elevation Program, or 3DEP, is one of the principal public sources for U.S. elevation and lidar data. It is best understood as a coordinated product ecosystem rather than a single downloadable dataset. At its foundation are lidar point clouds and other elevation source data; from those sources, USGS publishes standard DEM products at several resolutions, including 1-meter, 3-meter, 10-meter, and 30-meter products where coverage exists. The program also includes Alaska-specific products derived from interferometric synthetic aperture radar, or IfSAR, along with contours and supporting metadata. 3DEP data is distributed through The National Map, USGS services, ScienceBase, and related download and cloud-access systems. The data is free and public domain, but a defensible analysis still requires checking the exact product, acquisition date, quality level, coordinate reference system, vertical datum, processing status, and known issues for the area of interest.
How EDK fits
For: GIS analysts, remote-sensing and Earth-science researchers, hydrologists, civil and environmental engineers, land managers, emergency planners, cartographers, infrastructure teams, and developers building elevation-aware geographic applications.
3DEP is a strong example of how a physical-world dataset becomes useful when it is connected to other geographic features. Elevation is not meaningful only as a shaded-relief image; it changes how roads, buildings, streams, drainage assets, utility corridors, land parcels, vegetation, and infrastructure are interpreted. A world model can use 3DEP as a terrain layer for locating and comparing physical features, measuring their relationship to slopes and drainage, and computing geographic properties such as elevation, relief, visibility, watershed position, or distance above nearby water. The important distinction is that 3DEP supplies authoritative external elevation products; it does not by itself provide a complete inventory of every road, building, address, or public asset. Its value comes from making terrain available as a computable geographic context alongside those other feature classes.
- •Combine 3DEP elevation and slope derivatives with roads, buildings, streams, drainage structures, or infrastructure to identify terrain constraints, low-lying assets, steep access routes, or areas where physical features intersect modeled runoff paths.
- •Use elevation queries, raster summaries, watershed boundaries, and proximity calculations to compare physical features across neighborhoods, municipalities, or regions while preserving the source product, acquisition vintage, resolution, and vertical datum used in the computation.
- •Relate lidar-derived terrain and surface information to imagery, land cover, construction activity, vegetation, or environmental observations to analyze how physical conditions change across the landscape. However, the specific feature layers and computation must be supplied by the surrounding geographic system rather than assumed to exist in 3DEP.
Dataset profile
Formats
Cloud Optimized GeoTIFF and GeoTIFF for DEM products
IMG for selected 3-meter and legacy or product-specific elevation products
LAS and LAZ for lidar point clouds
Shapefile and File Geodatabase for contours
GeoPackage and CSV for spatial availability metadata
Product-specific formats for source DEMs and Alaska IfSAR products
XML for textual product metadata
Access methods
The National Map Downloader
The National Map Viewer and map services
USGS ScienceBase catalog
Data.gov and Geospatial Platform metadata catalogs
LidarExplorer and lidar availability viewers
DEM Availability Viewer for 1-meter DEM coverage
REST, WMS, WFS, WCS, and related National Map services where available
Direct cloud or HTTPS access for selected products and metadata
Quality and limits
Resolution and coverage vary substantially by geography and product; a national label does not imply uniform local detail.
Acquisition dates differ by project, so a DEM may not represent current terrain after construction, grading, erosion, flooding, mining, or other change.
DEM values depend on lidar classification, interpolation, breaklines, hydroflattening, vegetation and structure handling, and other processing decisions.
Vertical datum and horizontal coordinate reference system must be checked for each product and region; they are not safely assumed to be identical everywhere.
Alaska includes important IfSAR and lower-resolution products, so workflows designed for conterminous-U.S. lidar may not transfer directly.
Lidar point clouds and high-resolution rasters can be computationally expensive to download, index, mosaic, and process.
Known issues and project-specific corrections may affect individual products; analysts should review USGS notices and metadata before high-consequence use.
3DEP is elevation-focused and does not provide a complete, current feature inventory for roads, buildings, addresses, parcels, utilities, or public assets.
Analysis workflows
Select the analysis extent, physical question, required scale, and acceptable uncertainty before choosing a 3DEP product.
Use The National Map availability tools and WESM metadata to identify product status, work unit, acquisition date, quality level, and project links.
Choose a seamless DEM for regional terrain summaries or a 1-meter DEM and lidar point cloud for supported site-scale work.
Download or stream COG tiles, or obtain LAZ point clouds for custom point-based modeling; retain original metadata and product identifiers.
Confirm horizontal and vertical reference systems, units, NoData behavior, tile overlap, and source acquisition dates.
Derive slope, aspect, hillshade, curvature, flow direction, flow accumulation, topographic position, viewshed, or watershed products according to the research question.
Condition hydrologic surfaces cautiously and compare modeled drainage with authoritative hydrography, known channels, culverts, and field or engineering information.
Join terrain summaries to roads, buildings, infrastructure, land cover, imagery, administrative areas, or environmental observations using documented spatial relationships.
Validate fine-scale or high-consequence results against checkpoints, local surveys, recent imagery, project reports, or other authoritative sources.
Publish reproducible outputs with source product names, tile identifiers, acquisition dates, vertical datum, processing software, parameters, and limitations.
Value inside EDK
What USGS 3DEP contains
3DEP has two closely related sides: source elevation data and standardized elevation products. Lidar point clouds are the foundational three-dimensional observations for much of the conterminous United States. They preserve classified returns and can support terrain extraction, canopy or surface analysis, point-density inspection, and custom elevation modeling. USGS distributes lidar point clouds primarily in LAS and compressed LAZ formats. (usgs.gov)
Standard DEM products provide gridded elevation surfaces at several scales. USGS lists 1-meter DEMs, 1/9-arc-second products at approximately 3 meters, 1/3-arc-second products at approximately 10 meters, 1-arc-second products at approximately 30 meters, and 2-arc-second products at approximately 60 meters for Alaska. Availability is not identical everywhere. A 1-meter DEM may exist for one county or lidar work unit while a 10-meter or 30-meter seamless product is the appropriate regional layer elsewhere. The program also offers 1:24,000-scale contours, source or original-product-resolution DEMs, and IfSAR-derived digital surface models and orthorectified radar imagery in Alaska. (usgs.gov)
- •Lidar point clouds: LAS and LAZ.
- •Bare-earth and seamless DEM products at multiple resolutions.
- •1-meter DEMs and source-resolution DEMs where higher-resolution lidar coverage exists.
- •Alaska IfSAR digital surface models and orthorectified radar imagery.
- •Contours, metadata, quality information, project reports, and availability indexes.
Geography, temporal coverage, and update cadence
3DEP covers the United States and its territories, but geographic coverage and resolution vary. The conterminous United States has the strongest lidar-based coverage. Alaska relies substantially on IfSAR and lower-resolution products, although higher-resolution lidar and IfSAR products are available in some areas. Hawaii and island territories can also have product-specific coverage rather than a single uniform resolution. USGS availability viewers should be consulted for the exact area of interest rather than assuming that a national product has identical detail everywhere. (usgs.gov)
3DEP does not have one simple update cadence comparable to a weekly or monthly global file. Elevation projects are acquired, processed, validated, and published by work unit. USGS states that seamless data is updated continually as new source data becomes available, while the WESM spatial metadata is written almost daily as additional lidar projects are processed and published. Consequently, two neighboring areas may have different acquisition dates and different publication or replacement histories. (usgs.gov)
- •Geography: United States, Alaska, Hawaii, and U.S. territories, with product-specific coverage differences.
- •Temporal coverage: varies by lidar or IfSAR project and work unit.
- •Update behavior: ongoing and project-based; WESM is updated nearly daily as new work units are published.
- •Vertical references: commonly NAVD 88 in the conterminous United States, but the applicable vertical datum varies by region and product.
Formats, access methods, and a defensible GIS workflow
The National Map Downloader is the primary public discovery and download route. USGS also provides The National Map services, including REST, WMS, WMTS, WFS, and WCS endpoints for applicable products. Downloads and map services are free, and USGS states that no account is required. ScienceBase, Data.gov, and the Geospatial Platform can provide catalog or metadata access for selected products. (usgs.gov)
Standard DEMs are distributed primarily as Cloud Optimized GeoTIFFs, or COGs. COGs remain compatible with ordinary GeoTIFF software while allowing applications to request only portions of a raster over the network. Lidar point clouds are distributed as LAS or LAZ, and contours are available as Shapefile or File Geodatabase products. The exact delivery format can differ for source products, especially in Alaska, so inspect the product record before building an automated importer. (usgs.gov)
- •Raster processing: mosaic tiles, reproject only when necessary, derive terrain variables, and preserve vertical units.
- •Hydrology: condition DEMs cautiously, inspect hydroflattening, and validate modeled channels and divides against known hydrography.
- •Lidar processing: inspect classifications, point density, acquisition date, and quality level before generating custom surfaces.
- •Cloud workflows: use COG range access for raster subsets and LAZ-compatible tools for point-cloud processing.
- •Reproducibility: record product identifiers, tile names, download dates, source acquisition dates, software versions, and processing parameters.
Licensing, strengths, limitations, and tradeoffs
USGS describes 3DEP products as free of charge and without use restrictions, and USGS documentation identifies the products as public domain. Users should still retain provenance, metadata, and attribution where practical, especially when distributing derived products or documenting a scientific or public-sector workflow. (usgs.gov)
The principal limitation is variability. 3DEP is assembled from projects collected at different times, with different sensors, resolutions, land-cover conditions, quality levels, and processing histories. A high-resolution lidar DEM is not automatically a bare-earth truth surface for every location: vegetation, buildings, bridges, water, breaklines, interpolation, hydroflattening, and classification decisions affect the result. USGS also maintains a known-issues page, so project-specific corrections and processing notices should be checked before treating a surface as authoritative for a high-consequence decision. (usgs.gov)
- •Strength: public-domain elevation and lidar data with broad U.S. coverage.
- •Strength: multiple resolutions and source products support both regional and site-scale analysis.
- •Strength: official metadata, quality information, availability maps, and standardized national distribution.
- •Tradeoff: coverage, acquisition vintage, resolution, and vertical accuracy vary by location.
- •Tradeoff: large lidar point clouds require substantial storage, indexing, and processing capacity.
- •Tradeoff: DEMs are derived surfaces and may not represent current conditions or every terrain feature with equal reliability.
Questions teams ask
Is USGS 3DEP one dataset or several datasets?
3DEP is a coordinated family of elevation products and services. It includes lidar point clouds, seamless DEMs at multiple resolutions, source-resolution DEMs, contours, Alaska IfSAR products, metadata, availability indexes, and map services. The correct product depends on the geography, resolution, terrain question, and required level of detail.
How current is USGS 3DEP data?
There is no single national acquisition date or fixed refresh interval. Products are collected and published by project and work unit, and USGS updates the program as new source data becomes available. Always inspect the acquisition date and publication status for the specific tile or work unit. The WESM metadata is updated nearly daily as additional projects are processed and published.
What resolution should I use for a GIS analysis?
Use the coarsest resolution that preserves the phenomenon being measured. A 30-meter or 10-meter seamless DEM is often suitable for regional terrain, watershed, or landscape analysis. A 1-meter DEM or lidar point cloud may be appropriate for site-scale drainage, grading, infrastructure, or detailed terrain work, but only where coverage and validation support that use.
Is 3DEP elevation data free to use?
USGS states that 3DEP products are available free of charge and without use restrictions, and its documentation identifies the data as public domain. Preserve source metadata and provenance in derived products, especially when the results support scientific, engineering, regulatory, or public-facing decisions.
Can 3DEP be used to determine the elevation of a building or road?
It can provide terrain or surface-elevation context near a building or road, but the answer depends on the product. A bare-earth DEM estimates ground elevation, while lidar returns and surface models can include vegetation, structures, or other above-ground objects. The feature’s exact location, the selected product, point classification, resolution, vertical datum, and acquisition date must all be checked.
Keep exploring
nasa srtm
SRTM is a complementary elevation dataset for broad regional and global terrain analysis, while 3DEP provides more detailed and more geographically focused U.S. elevation products.
landsat collection 2
Landsat Collection 2 supplies time-series optical Earth observation that can be combined with 3DEP terrain for land-cover, vegetation, urban, environmental, and change-analysis workflows.
tiger line
TIGER/Line provides U.S. geographic frameworks such as roads, boundaries, and statistical areas that can be joined to 3DEP-derived elevation and terrain metrics.
Sources
About 3DEP Products & Services
Official USGS overview of 3DEP product families, free access, use restrictions, and the relationship between lidar point clouds and DEMs.
Open sourceWhat types of elevation datasets are available, what formats do they come in, and where can I download them?
Official USGS reference for resolutions, formats, The National Map access, COGs, LAS/LAZ, contours, and source elevation products.
Open source3DEP Spatial Metadata
Official documentation for WESM work-unit metadata, acquisition dates, quality levels, product status, and project links.
Open source3DEP Product Metadata
Official description of textual XML metadata and spatial metadata supplied with 3DEP products.
Open source3DEP Known Issues
Official source for corrections, processing problems, and known issues that can affect interpretation of 3DEP products.
Open source