Jim Logajan writes:

In my sectionals the Legend says:

"Class E Airspace exists at 1200' AGL unless otherwise designated as
shown above."

together with:

"Class E Airspace low altitude Federal Airways are indicated by center
line."

So a Federal Airway is Class E, and between the text quoted above from
the Sectional Legend and the airspace markings on it, the base altitude
of the Victor airway appears "published" to me. Pick a spot on any airway
and you should be able to determine the base of Class E that marks its
base.

Where can I find the MEA of V134 between PACES and SLOLM on the sectional
chart?

Anyway, according to Rod Machado's Private Pilot Handbook, the base of
Class E is raised along many Victor airways in mountainous regions in
order to avoid terrain from blocking VOR signals, not so as to avoid
obstacles to flight.

The base of Class E is is not necessarily the minimum altitude for an airway
within that airspace.

However, there may be some confusion here. If you fly VFR, all you have to do
is stay clear of terrain and obstacles, which you can do most of the time by
just looking out the window. The sectional will give you an idea of terrain
beneath you, although if you are looking at the sectional for this information
in flight, you're probably not in VMC any more. The sectionals don't actually
indicate the altitudes that you must fly, though--you have to infer this from
other information on the chart.

If you fly IFR, you must maintain minimum altitudes on airways, and you cannot
find these on the sectionals (the sectionals don't give any minimum altitudes
for airways). Instead, you look at an IFR chart, which does indicate the
minimum altitude for each portion of an airway. The IFR minimums are usually
more generous than you might fly when under VFR.

In good weather in areas with high altitudes, I may fly VFR in order to be
able to avoid the generous MEAs that would be required for IFR (and thereby
avoid the need for oxygen). In mountainous areas, though, this advantage must
be balanced against the specific risks of mountain flying.