This book was a childhood favorite I recently hunted down and re-read; there are very few copies left in existence and it seems it was mostly sold to school libraries.
This is the story of the author's great-grandmother, Yellow Leaf, a young Cherokee girl who became separated from her family along the Trail of Tears. She is found by Cagle, a white trapper who grudgingly takes her in when her family cannot be found, and soon grows to love her like a father. When Yellow Leaf is older, she feels compelled to look for her family, even though the trip will be frought with danger.
This book reminds me of Paulsen's Tuckett's Travels series, which also has a teenager separated from his family in the West during the same time period. I didn't remember much of it and was worried I'd be disappointed or that it might have content considered offensive now, but I liked it just as much now as I did then.