Answer as many questions as possible about the indigenous people in outer Manchuria.

1, I don't know, compared with immigrants from Europe, it should be a small population and a large area. This is the conclusion from looking at the map.

2. It should be similar to the northeast, and I can only confirm the Hezhe nationality (the area is uncertain, it seems that there is at least one on the east bank of Wusuli). More or all of them moved from Gyeonggi Province (Jieya River) to Daxinganling. Is there anyone in the same place now? There should be more.

I don't know.

4. Who knows your problem? I doubt that anyone can answer. That's all I know. Not necessarily right, but I can't make it up.