Several web services are available that provide access to elevation data. This package provides access to several of those services and returns elevation data either as a SpatialPointsDataFrame from point elevation services or as a raster object from raster elevation services. Currently, the package supports access to the Mapzen Elevation Service <https://mapzen.com/documentation/elevation/elevation-service/>, Mapzen Terrain Service <https://mapzen.com/documentation/terrain-tiles/>, Amazon Web Services ...