RadioBanter - performance of Gorge-mounted dipoles?

All,

I have an antenna puzzler for you all.

My trailer is sitting on one side of a 60 foot high mesa resting on top
of a vast desert plain.

On the edge of the mesa is a gorge that opens outward, forming a Vee.
The two points
of the Vee, on the mesa, are about 180 feet apart. The bottom of the
gorge slopes gently
down to the plain, such that the edges of the Vee are 40 foot higher
than the bottom of the
gorge, and 30 feet away from where the gorge begins to open from the
mesa.

What this means is that I could possibly hang a rope mounted dipole in
free space,
using guy anchors hammered into the Vee points in the mesa dirt. I
possibly could even
hang reflectors at the appropriate intervals on either side of the
dipole to create
a non-rotating wire Yagi.

My question to you all is this: will the antenna's performance be
defined by the fact
that it is hanging 60 feet in free space over the plain, or will this
be nullified by the
geometry of the gorge immediately behind and below the antenna?

Keep in mind that soil conductivity is very poor in the desert. I plan
on using this
for transmitting only, I discovered two lines of wood supported wire
fencing on
which I could mount lay wire atop for receiving beverages. Each of
these lines
go on for thousands of feet and cross at right angles only a hundred or
so feet
from the trailer.

Thoughts?

The Eternal Squire