Some interesting information in a press article.

This is new to me:

A Plains Indian warrior would sometimes become ill with Mercury poisoning after unknowingly painting his forehead, face or other areas of his body frequently with a natural substance Mercury-lined pigment dye before hunting or participating in a raid or battle.
They also mention lead-poisoning, from the habit of carrying musket-balls in the mouth.

This on their height:

The Plains Indians were not very tall people during the 1800s. The average height of a Plains Indian was 56 - 59 tall.
This is quite interesting -- since one sometimes hears quite wild figures based, I think, on estimated heights of individuals in literary sources.

I've seen a fairly comprehensive survey of bone material over time -- It's online but I can't recall where now -- and I think that was giving 5′ 9″ as an average height (or perhaps it was 56 - 59 as here). Obviously, some individuals were taller, and some tribes seemed to have been on average, too. I think the Crow were said to have been. The Oasge were geneally reckoned the tallest (they were on the edge of the Plains and farmed as well). But we seem to have an average height that's comparable to some prehistoric populations -- and to the height in current First World countries -- but not, on the whole, greater.

It's interesting that the ages of white captive boys were sometimes under-estimated by U.S. Army medical officers examining them: The Captured: A True Story of Abduction by Indians on the Texas Frontier (9780312317898): Scott Zesch: Books

It's suggested by Scot Zesch that this underestimate of age occured, because perhaps these boys hadn't grown as much as they would have at home. Yet while these children had what we would consider a tough time, the boys seem on the whole not have been treated any more harshly than their captors' own male children, and not deliberately underfed.

It's certainly interesting. It's something of a regular claim in Paleo Diet circles that hunters must always be bigger than agriculturalists. That certainly can be true, but it doesnt always seem to be so.

Anyway, I've gone into a digression. Here's the article -- also inludes three linked YouTube videos, which I haven't seen yet:

Op-Ed: Michael Bad-Hand Terry talks at Oregon Trail Interpretive Center (Includes first-hand account)