The more you examine the relationship between the native Americans and the LDS church, the worse off the LDS church appears.
In 1830 Joseph Smith produces a book which is based on the theory that the native American population are the remnants of a lost branch of Israelite. A book avowedly written to bring these natives back to Christianity. Inherent in this thesis is the belief that native American culture of the 1800s is sub standard, could not have been responsible for the extant archaeological remains and that Christianity is a superior belief than their own religious practices.
Joseph Smith takes several steps to try and convert the American Indians to Mormonism, all of which fail, some of which include receiving a revelation from God which instructs him to send married Mormon men to the Indians to take additional wives.
Verily I say unto you that the wisdom of man in his fallen state, knoweth not the purposes and the privileges of my holy priesthood. but ye shall know when ye receive a fulness by reason of the anointing: For it is my will, that in time, ye should take unto you wives of the Lamanites and Nephites, that their posterity may become white, delightsome and Just, for even now their females are more virtuous than the gentiles.
Fast forward to 1850's and Mormon immigrants invading the Great Basin. Upon arrival there they find a thriving Indian population dependent on hunting and fishing for the most part. Within 50 years the native populations have been decimated and driven from their native habitations to reservations by a culture who believe in the Book of Mormon, a book specifically brought forth by God to save the very people being destroyed by the Mormon immigrants.
So now in the 1950's these same Mormons under the guidance of living prophets, feeling sorry for the conditions of these poor Indians having to live on the very reservations they forced them to live on, offer them the chance to improve their children's lives (why bother with the parents after all) by taking them away from that awful reservation and teaching them how to be white and Mormon.
Well at least we can feel better about what we did because it was all done with good intentions and because, dangit, God wants us to save these poor savages from themselves.