The USGS Hillshade (or Shaded Relief) is a type of base map that uses shading to show elevation across the contiguous United States, Alaska, Hawaii, and U.S. territories. It's made from the 3D Elevation Program (3DEP) which offers the best elevation data in a seamless format. This map uses a technique called hillshade, which simulates shadows to represent changes in terrain. The light in this map seems to come from the northwest at a 45-degree angle, making the features look more three-dimensional.
The map uses the highest resolutiuon data available, but resolutions vary accross the USA. The colors on the map range from white to brown, created by applying specific RGB (red, green, blue) values to show elevation levels.
For more details on the 3D Elevation Program (3DEP) used to create this map, go to https://www.usgs.gov/3d-elevation-program.
Service URL: https://basemap.nationalmap.gov/arcgis/rest/services/USGSShadedReliefOnly/MapServer
Originator: USGS