Im writing a research paper on mixed families in Native American society and their influence on native society, but finding sources on Native American intermarriage are becoming "scarce"
Two great books: Sylvia Van Kirk's Many Tender Ties, and Jennifer Brown's Strangers in Blood. They came out roughly the same time, both about relations and intermarriages between HBC and NWC employees and Indigenous women.
I dunno what your time period is, but I have read about some stuff, though it's mostly from the European side.
There are a lot of "captive" narratives present (just google captive narratives) throughout the mid 1700s to late 1800s. Generally, a lot of them seem to share a theme of "young European American girl is kidnapped or taken in after the rest of her family is killed in a raid, and she's raised by the tribe and may or may not marry into them and have kids before being discovered by other Europeans again". Boys and adolescents were also taken captive frequently, but there seems to be fewer accounts of guys actively marrying into the tribe and having kids.
Beyond that though, be sure to look up Metis culture. A lot of French, British, and Northern Irish trappers in the Great Lakes region took native women for wives, and their kids are called "metis" on account of that mixing of cultures. Jane Johnston Schoolcraft, one of the first Native American poets, was the product of such a marriage and also married another white man, Henry Schoolcraft, who was also the first Indian Agent. Basically a whole society grew up around these mixings in that region and there's some pretty cool stuff on it.