I need a two radio system to keep in touch with my men in the field in
mountainous NE Pa.   I would need 5 or 6 units each with a range of
approx 20 miles.  I guess that I would also need some sort of home
base.    What should I do?

Paul

The mountains are the problem. Even using high power or very high gain
antennas, you will occasionally not be able to communicate even ten
miles. The Motorola Indium satelite system did the job, but it was too
costly, so it was sold to the USA military and I don't think it is
presently available unless you are a DOD contractor. Back scatter and
forward scatter will work 98% of the time, but the equipment is
costly, bulky and heavy, plus you probably can not get a licence to
use it, unless each unit has a general class ham radio operator. I
presume none of the cellphone companies reliably cover the area you
are interested in?  Neil