How do I know if the DEM contains z-values ? By looking at the DEM's layer properties and it does not mention the z values. I then add it to the ArcScene and tried to find it..nothing...
It only shows the x,y values.
You should see a value which the image is stretched by when you add it to arcmap.
Then by switching to stretch type mni-max you will see a more accurate elev value.
which produces this
A nice touch then is to use the usgs color pallette to show elev.