I can only post this now that I have completed biking through a handful of Indian Reservations and I hopefully avoided unnecessarily scaring my parents. I have probably biked through 5 different Indian Reservations in Utah, Colorado, Montana and Minnesota. It never failed that before entering these lands those living outside of the reservations would warn me, "I would not ride on the res. if I were you, don't stop anywhere, it is very dangerous, they are crazy people etc." I understand from learning about the statistics that awful crimes occur on a multitude of reservations. In the same breathe if people look into the actual crimes it is typically at night, when the people are drunk or on drugs and frequently between people on the reservations that get mixed up with the wrong people. I am not discrediting the warnings and I understand that people aim to protect me, but it seems to me a great deal of judging and stereotyping goes on against Native Americans. I can only speak about what I have experienced while biking through reservations: very friendly, generous and helpful people, tons of trash (including libation trash and cigarettes) and a general "run down" look to the towns.
I will admit that while biking through the reservations I have my safety antenna up and am aware that people have warned me of potential danger. I also have to admit I have enjoyed all of the interactions between the people I have met while spending time on the reservations.
I do not know the absolute truth, but it hurts my heart that many awful crimes happen on the reservations and many people not living on the reservations make awful stereotypes about people living on the reservations.