>
>
> My eTrex Vista from Garmin has two altimeters.  One via GPS and
> another via barometric pressure.  Seems accurate within the indicated
> range (less than 50 feet almost always, 18 feet regularly).  I leave
> the unit on my dash, or use it's optional handlebar mount on my
> bicycles.
>
>

A decent aneroid altimeter should easily handle sub-contours on a topo
(20 feet on the old stuff, 10 on the new). A good altimeter will show
you the altitude in feet... accurately. My dad had one that would show
you the distance between the desktop and the floor.

Jim