SF: Man infiltrates alien society based on barbarian nomadic society. 80's?

Roughly 25 years ago I read a book in which the protagonist disguises himself as a local on an alien world to gather information regarding harvesting a natural resource. The inhabitants of this world were based on a nomadic culture similar to ancient Mongolian tribes and were divided into clans like wolf clan and bear clan etc. I remember a more civilised society existed on this planet south of a huge cliff that the northern barbarians could not descend to invade until the protagonist shows them how using his rock climbing skills.

If anyone recalls this book, please help as I would very much like to re-read it to take me back to my youth :)

Thanks

Maybe Harry Harrison's Deathworld 3. It's been a long time since I read it, but the summary at Wikipedia seems to match.

Yes that's it, thanks a lot for your help and swift reply!

You're welcome.