Now the daughters of Hepher's son Zelophehad, Gilead's grandson, who had been fathered by Machir, who had been fathered by Manasseh, from the tribe of Manasseh, the direct son of Joseph, were named Mahlah, Noah, Hoglah, Milcah, and Tirzah. They approached

These were Gilead’s descendants:
the Iezerite clan from Iezer;
the Helekite clan from Helek;

Manasseh’s descendants:
the Machirite clan from Machir.
Machir fathered Gilead;
the Gileadite clan from Gilead.

That's why Moses gave Gilead to Manasseh's son Machir, who lived there at the time.

telling them, "If the descendants of Gad and descendants of Reuben cross over the Jordan River with you, that is, all of their soldiers who've been equipped for battle in the LORD's presence, so that the land is subjugated right before your eyes, then you are to give them the land of Gilead as their possession.

The descendants of Manasseh's son Machir attacked Gilead and then captured and dispossessed the Amorites who were there.

The leaders of the ancestral families of the descendants of Gilead, who were descendants of Machir, and descendants of Manasseh, from Joseph's tribe, approached and spoke to Moses and the leaders of the ancestral houses of the Israelis.

Now the children of Reuben and the children of Gad had a very great multitude of cattle: and when they saw the land of Jazer, and the land of Gilead, that, behold, the place was a place for cattle;

Our little ones, our wives, our flocks, and all our cattle, shall be there in the cities of Gilead: