Be sure everyone in the party has a pair of rubber boots in their inventory, or they'll be taking damage fast from the slime on the floor. Better save now, since there is a good probability that the boots will be destroyed before you finish the cave. If that happens, just reload. There's also a spare pair of boots in a room to the south, near the entrance, beyond a pool of green slime and a gecko.
Basically, what you need to do is fight your way through the caves,
find Smiley (the missing trapper) and escort him out of the caves.
You may also want to try to repair the power generator in that room,
while you're there. Doesn't seem to give any xp, though. Speaking of
the generator, apparently that's half of what's needed to use the
elevator there. It says you need an electronic device to open it.
I came back there much later with a mark II electronic lockpick, and
you can enter and go down into a sort of small ruined depot. There's
decent stuff in there, such as a Mark II Combat Armour, but by the
time you do get the electronic lockpick and enough skill to open this
door, you probably have much better equipment already. There's a
sentry robot down there with a rocket launcher. Like all explosives
in the game, missiles are IMHO beyond crappy, but he launches three
missiles per turn. Again, by the time you get the electronic
lockpick, you can probably survive that quite easily. Also in there
you can find some 4.7mm caseless ammo, some 2mm EC ammo for your Gauss
Pistol, a Bozar and some .223 ammo for it, plus some other stuff.
After escorting Smiley out, go back to Klamath and talk to him in the
bar. He'll teach you how to skin geckos. Now those pelts do fetch a
decent price, particularly the golden gecko ones. Which, given the
game's general cash shortage, can be very welcome. On the other hand,
they're also much too heavy for the price, if you ask me. Me, I'd
rather carry a spare gun from a robber's corpse, since it sells
better and weighs less.
He'll also teach you a little outdoors skill. About as much as you'd
learn from a book, but it's still an improvement. Mrs. Buckner will
give you 100 bucks if you say you don't need a reward. Or, if you
haven't taken Sulik yet, you can get him for free now.