Why do Native Americans look more caucasoid than Eskimos?

This is not supposed to be a stupid question. I am asking an honest question. If you compare faces and pictures of Native American people (Iroquois, Algonquin, Cherokee, Choctaw, etc.) you will notice that their faces look more caucasoid than the Inuits/Eskimos even though both groups are considered Amerindians (a branch of Mongoloid race). I was wondering if anyone can answer this question for me.