Well, I wiki-ied it to be sure I knew the difference between Wounded Knee and Little Big Horn, which shows you how much I know.
I had US History as a high school sophomore, so 1982. It was an Advanced Placement class, which means if you do well, some colleges will give you credit for it. (And an 'A' was worth 5 points instead of 4, so your GPA was given a boost.) This is all to say that it should have been a good class.
But like much of my high school experience, it was basically an exercise in the memorization of facts, dates, and people. There were no essays or research papers to delve into topics with any depth. If memory serves we spent more time on the Teapot Dome scandal and Huey Long. And we didn't make it past WWII.
In general, Native American history as related to white settlers was glossed over or (I realize now) rewritten to a degree. I was in Tennessee, and Andrew Jackson was a hero there, the Trail of Tears notwithstanding.
I imagine the answer varies widely by where you live, public or private school, and the teacher's personal points of view.
Things may be different now. If I were you, I'd put this on FB, maybe craft specific questions, and ask friends to share it so you can find out what kids and their parents know about how it is taught today. Maybe set up an email account especially for responses?