Night flying in the mountians in a cessna 150,

But we say "the Appalachians".

And it would be correct to say "the Nevadas." But not "the Sierras."

But we write "the Appalachian range", though we write "the Sierra
Nevada", not "the sierra Nevada". "Sierra" is part of the proper noun;
it is not a common noun by itself in this context, the way "range" is above.

Jose
--
Nothing is more powerful than a commercial interest.
for Email, make the obvious change in the address.