World is segregated by impenetrable fog, expedition makes it across and there are tribes with dragons.

The dragons are dying out due to inbreeding basically and they all go to war. Main character is a female anthropologist or sciencey type

I read it a few years ago but can’t remember. TIA!

Edit to add more details: there are different tribes with different types of dragons, ice, sea, etc. there’s one type of dragon extinct. To become a dragon you take herbs or something then have to catch the dragon spirit and hold it. The woman becomes the type of extinct dragon in the end.