I have been trying to retrieve an USGS 1 Arc Second DEM by state or full Continental US. When using the TNM Download tool for Elevation Products (3DEP) I am having trouble isolating data by state or Continental US. There are multiple ways to isolate the data ie coordinates, polygon, current extent, and search. None of the options I have found provide a seamless DEM of the US or by state. Any advice would be greatly appreciated.