Thanks for your quick reply.
Here is what I experienced… When I zoom in, through wi-fi it will bring the contour lines in full rez. When I zoom out, that area is now highlighted. If I turn off wi-fi and also turn off mobile data, turn phone off and on, I can go back to the app and those areas are still highlighted and at full rez. This is all without manually selecting and downloading a region.
So I am assuming they are getting stored somewhere. Not a big deal if they don’t take up too much data.