I have been looking forward to making these 13-power mammoth riders. I have all the appropriate techs researched and buildings built, but I lack Ivory.
Now, the Doviello are my vassals (I took their capital and they only have a small mountain village left, NE of the capital). To the west of the capital is a source of Ivory, within my cultural range (a workable tile within the fat cross, in fact). However, no matter how many techs I research, my workers refuse to build a camp on it...whenever I put a worker there, there is not even a button (greyed out or otherwise) for making a camp...help ?!

Ivory must be obtained through mammoth camps...which aren't built by workers but by captured mammoths. Actually, mammoth camps can be built on tiles lacking ivory, and create it there. I think that mammoths can also be upgraded to mammoth riders without the need for the ivory recourse.

If a mammoth camp gets pillaged, I'm pretty sure you are out of luck for that source of ivory.

Your could rebuild it with another mammoth, but it would probably make more sense to build a new one elsewhere.

How do you capture a Mammoth (or other animal) again?
Playing the scenario for the first time, and haven't figured it out right yet.

Simple enough, just get a recon unit with the Subdue Animals promotion to beat one. Captured animals start out almost dead though, so you'll need to have some guards for it or it'll probablyget killed by something nasty.

Many thanks for this thread. I was having the same problem and could not work out how to capture the mammoths. This could be the difference between victory and defeat!

I'm having a fantastically epic game (second attempt) and loving the scenario so much, it has made me forget about the xOTM!