Thanks for that link.
We visited Mount Rushmore 3 years ago. The Indians are always whining about it. There are days that are blacked out for visitors because they claim that they are sacred days. Turns out many of the days are around holidays when people would have off work and might want to visit.
From what I can gather, the Lakota Indians who claim Mt. Rushmore is sacred ground, stole it from the Cheyenne, who had previously occupied the region. Next time they protest, maybe a group of Cheyenne activists should form a counter-protest and demand reparations from them.
The Sioux that claim it as their land stole it from Crow (?) after their got driven from the east by, I believe it was the Iroquois.