Introduction
The U.S. Geological Survey has completed one of the largest mapping efforts in American history. As of the end of fiscal year 2025, the 3D Elevation Program (3DEP) had achieved 99% baseline coverage across the United States—meaning lidar data or interferometric synthetic aperture radar data (for Alaska) is either available or in progress for nearly the entire country .
At Geo Week 2026, USGS officials announced that the baseline data acquisition is complete. What began as a vision many called impossible has become the largest national elevation mapping effort in the world, built on a billion dollars in funding and the contributions of hundreds of partners from every level of government and the private sector .
But completing the baseline is not the end. It’s the foundation for something more ambitious: the 3D National Topography Model (3DNTM) —a landscape-level digital twin that integrates elevation and hydrography data to model the nation’s topography in three dimensions .
What 3DEP Actually Is
3DEP is not simply a map. It is a massive collection of lidar point clouds—precise measurements of the Earth’s surface generated by firing laser pulses from aircraft and measuring the return time. Each point represents a location on the ground, and collectively they form a detailed 3D representation of terrain, vegetation, and built structures.
The program has accumulated 76 trillion lidar points across the country . This data is freely available through The National Map and as an Amazon Web Services public dataset .
The program’s scale is difficult to comprehend. The USGS has merged more than 2,200 independently collected projects to create seamless coverage . The data supports an estimated $12 billion annually in user benefits, with applications spanning flood modeling, infrastructure planning, agriculture, and disaster response .
The Seamless 1-Meter DEM
One of the most significant technical achievements of 3DEP is the Seamless 1-Meter Digital Elevation Model (S1M) . Published for the first time in April 2025, the S1M provides consistent elevation data across large watersheds—essential for applications like flood modeling, storm surge analysis, and fire modeling that require data continuity beyond individual project boundaries .
The S1M is produced in 10 km by 10 km tiles and is designed to align vertically and horizontally with hydrography data . In FY25 alone, 377,000 square miles of S1M data were published .
The 3D National Topography Model: The Next Phase
The 3DNTM is the USGS’s framework for integrating elevation and hydrography into a single, coherent model. It comprises three components :
- Completing the 3DEP baseline —now 99% complete
- Developing the 3D Hydrography Program (3DHP) —a complete refresh of the nation’s surface water data
- Fully integrating elevation, hydrography, and other National Map data into a 3D data model
The goal is a “living model” —a landscape-scale digital twin that can track changes over time .
3D Hydrography Program (3DHP)
3DHP represents a generational investment in water data. It replaces the deprecated National Hydrography Dataset with elevation-derived hydrography (EDH) —surface water features generated directly from high-resolution lidar elevation data .
The technical approach is straightforward but powerful: high-quality lidar elevation data reveals the shape of the land, and algorithms identify where water would flow. This produces more accurate and complete stream networks than traditional mapping methods, particularly for headwater streams that were often missing from older datasets .
As of mid-2025, 3DHP had achieved roughly 10% nationwide coverage, with the program expected to take a decade to complete . The Texas Water Development Board approved a $500,000 cost-match contribution in March 2026 to produce 3DHP data for portions of Central and Northeast Texas, covering approximately 3,577 square miles .
The 3DHP data will be publicly available and is designed to support the “Internet of Water” —an interoperable framework for water data sharing and modeling .
Why Integration Matters
Bringing elevation and hydrography into alignment improves interoperability and achieves efficiencies. The seamless 1-meter DEM can be used to derive 3DHP surface water features, ensuring that elevation and water data tell a consistent story about the landscape .
This matters for practical applications. A flood model needs to know both where the water will flow (hydrography) and how high it will rise (elevation). When those datasets are aligned, the model is more accurate. The same is true for wildfire risk assessment, infrastructure planning, and agricultural management.
The Partnership Model: How 3DEP Gets Funded
One of the most remarkable aspects of 3DEP is its funding structure. The program relies heavily on partnerships that leverage federal investment with state, local, and private contributions.
In FY25, 3DEP data acquisition partnerships totaled $70.1 million in value**, with **$64.5 million contributed by partners . The FY25 Data Collaboration Announcement selected 26 projects across 14 states, contributing over 79,000 square miles of lidar data and 52,000 square miles of hydrography data .
The value proposition, as former USGS executive Kevin Gallagher put it, is simple: “For every dollar invested at USGS, we can bring four to five partner dollars to match” .
The Earth MRI program has provided $27 million in partnership funds for 3DEP lidar acquisition from FY2019 to FY2025, adding more than 355,000 square miles of new lidar data in areas permissive for hosting critical mineral deposits .
The Next Generation: Refresh and Change Detection
Completing the baseline is not the end of the story. About 61% of the contiguous United States has data that is five or more years old . Landscapes change. Forests grow. Rivers shift. Development alters terrain.
The next generation of 3DEP will focus on frequent repeat cycles and change detection. The 3D Nation Elevation Requirements and Benefits Study identified a strong signal for a refresh rate of four to five years .
This means the program is shifting from acquisition to maintenance. The goal is not just a snapshot of the nation’s topography, but a continuously updated model that tracks how the landscape evolves.
Practical Applications: From Wildfire to Flood
The value of 3DEP and 3DNTM data is best understood through its applications.
Wildfire preparedness and response. After the Eaton fires in Los Angeles County, high-resolution 3DEP data were released publicly within weeks, enabling partners to rapidly produce debris flow modeling, safety assessments, and restoration planning . The 3DHP data is being used for pre-fire planning, active suppression, emergency watershed stabilization, and long-term recovery—time-sensitive periods for post-fire hazard mitigation .
Flood risk management. The seamless 1-meter DEM supports consistent flood modeling across large watersheds. In southern Indiana, the East Fork of the White River project combined FEMA’s National Flood Hazard Layer with Indiana’s Best Available Flood Hazard Area, using statewide USGS 3DEP lidar to accurately delineate flood zones affecting agricultural land and rural infrastructure .
Critical minerals exploration. Earth MRI funding has directed 3DEP lidar acquisition to areas with potential for hosting critical mineral deposits, supporting domestic supply chain security .
Agriculture. A 2026 workshop is planned on agricultural usage of 3DEP, exploring how high-resolution elevation data can support precision agriculture and water management .
What Comes Next
The 3DEP baseline is complete. The 3DNTM is being built. The next generation of data acquisition is underway.
The USGS is focused on acquiring 100% 3DEP baseline by the end of FY2026 . The 3DHP program continues its decade-long effort to refresh the nation’s hydrography data. And the integration of elevation, hydrography, and other National Map datasets into a unified 3D model is progressing.
As Becky Anderson, Acting Director of the National Geospatial Program, put it: “When we say 3DEP, we’re not talking about maps. We’re talking about possibility. The 3DEP turns elevation into decisions” .
The United States now has the most complete high-resolution elevation dataset of any large country in the world. The question is what will be built on top of it.
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